U.S.-Vietnam maritime security cooperation in the South China Sea: From the Obama administration to the current Biden administration

Abstract U.S.-Vietnam security cooperation deserves scrutiny as tensions in the South China Sea continue to grow, especially with China’s growing aggressiveness and the Sino-American intensified rivalry. With a view to studying maritime ties between Hanoi and Washington, the article focuses on increased security and defense cooperation between the U.S. and Vietnam, with particular emphasis on the South China Sea issue under three consecutive U.S. presidents, namely Barack Obama (2009–2017), Donald Trump (2017–2021), and Joe Biden (2021-Present). By examining the trajectory of bilateral security relations, the article specifies that since the Obama administration, the U.S.-Vietnam partnership has not only been institutionalized but also achieved significant progress. The positive trend, which has arguably stemmed from growing convergence on mutual interests and shared concerns over the China threat in the South China Sea, is expected to considerably fuel the momentum of U.S.-Vietnam relations in the years to come, regardless of roadblocks on their cooperation.


PUBLIC INTEREST STATEMENT
The article focuses on increased security and defense cooperation between the U.S. and Vietnam, with particular emphasis on the South China Sea issue under three consecutive U.S. presidents, namely Barack Obama (2009-2017), Donald Trump (2017-2021), and Joe Biden (2021-Present).The article specifies that since the Obama administration, the U.S.-Vietnam partnership has not only been institutionalized but also achieved significant progress.The positive trend, which has arguably stemmed from growing convergence on mutual interests and shared concerns over the China threat in the South China Sea, is expected to considerably fuel the momentum of U.S.-Vietnam relations in the years to come.U.S.-Vietnam relations are approaching a tipping point, in which the two countries will celebrate the 10th anniversary of their comprehensive partnership in 2023.
interests and shared concerns over the China threat in the South China Sea, is expected to considerably fuel the momentum of U.S.-Vietnam relations in the years to come, regardless of roadblocks on their cooperation.

Introduction
U.S.-Vietnam relations have grown steadily, particularly during the three consecutive U. S. presidents, i.e., Barack Obama (2009-2017), Donald Trump (2017-2021), and Joe Biden (2021-Present), with prospects of bilateral partnership setting its own solid foundation.The two countries have expanded strategic and economic ties in the face of regional geopolitical uncertainties.Despite being former enemies, Vietnam and the U.S. have gradually turned the bilateral relationship from foes to friends, with the partnership improving significantly following the bilateral normalization in 1995.Both countries raised the relationship to the level of comprehensive partnership in 2013, opening a door for deepening bilateral collaboration on a range of issues, namely trade, culture, education, and security, among others.Despite ideological and political system divisions, coupled with lingering worries over U.S. intentions among Vietnamese conservative elites-the fear of "peaceful evolutions"-schemes backed by the U.S. that aim to topple or damage the Vietnam Communist Party (VCP) by means of unarmed combat, such as advancing human rights and democratic principles (Luong, n.d..), there have been ample opportunities for the two countries to upgrade the relationship to a level of strategic partnership, which would reflect the maturity of the bilateral cooperation.In other words, the current stable trajectory of U.S.-Vietnam relations has been established through a broad range of cooperation efforts in the tenures of Obama, Trump, and Biden 1 .
Vietnam has been considered the focal point of the U.S. outlook in the region for the past decade.In 2011, the U.S. marked a significant shift in its foreign policy priorities to Asia during the trip of former President Obama to Honolulu, Australia, and Indonesia for many meetings with regional officials (Lieberthal, 2011).Hanoi and Washington also signed a key Memorandum of Understanding (MOU) on Advancing Bilateral Defense Cooperation at the Second Defense Policy Dialogue, which paved the way for the robust growth of Hanoi-Washington over the next years, particularly in terms of maritime security (Thayer, 2018).While the Obama administration's Rebalance to Asia and the Pacific strategy emphasized strengthening closer relationships with Vietnam (Office of the Press Secretary, 2015), Trump's Indo-Pacific strategy, which was initially unveiled in Danang during the Asia-Pacific Economic Cooperation (APEC) CEO Summit on 10 November 2017, named Hanoi as the U.S. important partner (U.S.Department of State, 2019).The current Biden administration, while committing to maintaining a free and open Indo-Pacific region, also positioned Vietnam as one of its "leading regional partners" (The White House, 2022a).That being said, Vietnam has played an important role in Washington's strategic engagement, given that each of the U.S. presidential administrations from Obama to Biden has sought to exert its outreach in the region so as to maintain U.S. supremacy and deal with the rise of China (L.Tu, 2020).
In terms of defense and security aspects, the flourishing trajectory U.S.-Vietnam relations have been developed on the growing convergence of interests, considering both countries' commitments toward a rules-based order in the Indo-Pacific region and their shared concerns over China's alarmingly hegemonic ambitions in the South China Sea ("Biển Đông" in Vietnamese) 2 .Although the U.S. is not a claimant in the sovereignty and maritime disputes in the South China Sea, it has a vital interest in ensuring freedom of navigation operations in these crucial waterways, upholding international rules-based order and international laws, and promoting peaceful solutions to maritime conflicts-these principles are also in alignment with Vietnam's interests.Particularly, both Vietnam and the U.S. view the South China Sea's maritime security as one of their major concerns.For Hanoi, it is a matter of national security and prosperity, while for Washington, it is related to maintaining the U.S. dominance in the region and sustaining freedom of the seas (Ngoc Minh Trang, 2021).However, these interests are threatened in the face of China's increasing aggressiveness in the South China Sea (H.T. Le & Pascoe, 2020).While Vietnam condemned China's territorial claims in the South China Sea as a "serious violation" of its sovereignty over the two archipelagos, namely the Spratly and Paracel islands (Reuters Staff, 2012), the U.S. stated that overbearing Chinese behaviors "are undermining the international rules-based order, while its growing military capacity and capabilities are eroding U.S. military advantages at an alarming rate" (U.S.Department of Defence, 2020).
Vietnam has been on the front line of China's threats in the South China Sea as the country has faced perpetual varied forms of Beijing's gray zone tactics, ranging from geopolitical, economic, and military to cyber and information operations efforts (Lin et al., 2022).China's playbook includes militarizing artificial islands, putting pressure on neighboring states to withdraw oil and gas exploration projects, entering other countries' Exclusive Economic Zone (EEZ), and sinking other claimants' fishing vessels.Those provocations generated a deliberate policy change, pushing Hanoi towards closer ties with Washington (Huynh, 2020b).As evidenced in the Vietnamese Defense White Paper published in 2019, Vietnam noted that "depending on circumstances and specific conditions, Vietnam will consider developing necessary, appropriate defense and military relations with other countries . . .regardless of differences in political regimes and levels of development" (Ministry of National Defence, 2019).In this regard, there is still room for improvement in U.S.-Vietnam relations given ample opportunities for Washington and Hanoi to team up on joint initiatives at bilateral and multilateral levels on the South China Sea issue.
Consequently, the two countries' vital importance has been reinforced in each other's eyes.For the U.S., edging closer towards Vietnam in the maritime security sphere would enable Washington to solidify its presence in the region and serve as part of its long-decade strategy in an attempt to shape a balance of power in the maritime space (U.S.Department of Defence, 2020).In the eyes of Washington, Vietnam is among the few countries that are willing to stand up to China's coercions (Lichtefeld, 2021).Hence, supporting Vietnam in its maritime capacity-building and deterring China's growing clout is in accordance with the U.S. commitment to promote a free and open Indo-Pacific region.For its part, Vietnam seeks to move toward a closer partnership with the U.S. in a bid to prevent China from taking more assertive actions in the South China Sea (Hanh Nguyen, 2020).Facing the looming threats posed by China's ambition in the South China Sea, Vietnam has been left with little choice but to pursue a two-pronged approach to preserve its maritime territorial integrity.On the one hand, Vietnam is extensively modernizing its military capabilities, prioritizing the naval power aspects, after the US completely lifted the embargo on lethal weapons (Bich T. B. T. Tran, 2020).Still, given the politics of asymmetry regarding Hanoi's position vis-à-vis China's superior influence and capability, Vietnam, on the other hand, also seeks to forge strategic relations with extra-regional powers as a counterbalance to China's growing weight, in which stronger security cooperation with the U.S. is a well-crafted strategy to increase the costs on Beijing (Grossman, 2020).That being said, should China continue to act aggressively, and ignore international law and Vietnam's legitimate concerns in the South China Sea, Hanoi might be willing to speed up the security cooperation with the U.S. to navigate the China threat.In other words, the U.S. is the most unequivocal power in supporting Vietnam's response to China's effort to change the status quo in the South China Sea (Huynh, 2020a).

Literature review
There is a plethora of existing research on the U.S.-Vietnam security and defense cooperation regarding the disputed South China Sea issue.Hiebert et al. (Hiebert et al., 2014) provide an overview of the relationship between Vietnam and the U.S. through three main pillars of the partnership are highlighted in the report: (1) political and security cooperation; (2) commercial and investment linkages; and (3) people-to-people contacts.The authors contend that sustaining strategic ties with a partner like Vietnam will be essential to determining how the U.S. would pursue its goals in Southeast Asia.It is of great importance that the report makes crucial suggestions for strengthening political and security ties.Tu and H. Nguyen (2019) argue that Vietnam and the U.S. can be prospective security partners despite the political differences between the two countries.According to B. T. Tran (2019), despite ongoing difficulties, the two nations have made great progress in strengthening their defense, economic, and diplomatic ties.The author also gives instances to illustrate how cooperation on marine security has reflected the development of defense ties between Vietnam and the U.S. Indeed, Poling et al. (2021) state that the economic bonds between Vietnam and the U.S. seems to be on the upward trend, which is similar to the strategic relationship.As for the security aspects, Hayton (2018) points out indications for an emerging security partnership between Vietnam and the U.S. given a range of factors that have driven the bilateral relations, including the internal priorities of VCP's decision-making, China's aggressive agenda in the South China Sea, and U.S. response to manage its ties with the VCP.
In 1997, Rajan Menon used the terms of "strategic convergence" to highlight "a multifaceted cooperation and a convergence of views and interests on important questions of international security" when shedding light on the relations between Russia and China (p.101).The concept of strategic convergence, as further developed by Braekhus and Øverland, is "the overlap of key objectives and interests with regard to long-term developments in world politics, which provides the basis for extensive tactical cooperation between two or more states" (2007, p. 42).Convergence in this context refers to the act of converging and moving toward union or uniformity.As Menon (1997) puts it, the Sino-Russia ties in the 1990s were driven by self-interest calculations and a shared desire for leverage against third parties, rather than trust.Yet the growing ties between Hanoi and Washington, denoting conceptions of strategic convergence, have seemingly been enshrined by both shared common threats and mutual interests, with the strategic trust playing a vital role.The perspective is shared by recent academic discussions.Shoji (2018) argues that the convergence of strategic interests of the U.S. and Vietnam in the South China Sea propelled the two nations' security cooperation to move forward quickly.Specifically, since the 2014 oil rig incident, the re-emergence of the South China Sea issue as a result of China's increased excursions into these areas has been an important event that has accelerated Vietnam's security cooperation with the U.S. Similarly, Ton (2018) notes that the South China Sea issue is regarded as the key factor that has brought Vietnam and the U.S. together, while B. T. Tran (2019) raises a particular concern about China's growing assertive actions in the South China Sea has encouraged U.S.-Vietnam ties to improve.Meanwhile, Tu and H. Nguyen (2019) write that although Hanoi and Washington found a common ground in terms of the South China Sea issue, citing that both underlined the importance of resolving territorial disputes peacefully, these new advancements in maritime cooperation between the two nations should not be interpreted as just a response to China's increasing aggression in the South China Sea.One notable point of the article written by B. T. Tran (2019) is that strategic partnerships are more attractive than alliances, helping to explain Vietnam's careful approach to its relationship with the U.S. With the features of strategic partnerships, such as being flexible, non-binding, and multidimensional in nature, participating nations can gain benefits like economic or security without the risk of entrapment or loss of autonomy.
According to Thayer (2018), the U.S. was no longer an enemy but rather a potential partner to Vietnam.This change indicated that Hanoi had become aware of how closely its strategic interests converged with those of the U.S. In particular, maritime disputes in the South China Sea were the most crucial factor in determining how Vietnam and the U.S. strategic interests converged.The author argues that Vietnam and the U.S. have similar interests in maritime security, and political viewpoints, and support the full implementation of the Declaration on the Conduct of Parties in the South China Sea (DOC) and a legally binding Code of Conduct (COC) to support this point of view.By examining the growing strategic convergence in relations between Vietnam and the U.S., Thayer (2018) also provides several examples of how security and defense cooperation between the two nations is growing.He asserts that although the strategic goals of the U.S. and Vietnam in terms of defense and security cooperation are convergent, they are not congruent.
Yet little analysis has been done on the nature of the U.S.-Vietnam maritime security cooperation, particularly throughout the three consecutive American presidents between Obama and Biden.Cheney-Peters (2014) offers an outlook and conceptual framework for comprehending U.S. maritime security interactions in the Indo-Pacific.The author briefly covers bilateral cooperation indications but does not provide in-depth analysis or discussion of the ties' cooperation on the maritime security aspects.Meanwhile, Ton (2018) offers a critical analysis of Vietnam's geostrategic position, current maritime security issues, maritime strategies, and maritime policies, as well as how Vietnam has worked with other important regional powers to improve its maritime security.The paper identifies certain areas where Vietnam and regional powers might work together to maintain maritime safety and order in the South China Sea and the wider region.Accordingly, there have been ample opportunities for Hanoi and its partners to deepen collaboration in the fields of naval diplomacy, personnel training, marine situational awareness, and peacekeeping training.Nevertheless, a comprehensive analysis of the marine security cooperation between Vietnam and the U.S. was not covered in the study.
Based on the notions of "strategic convergence," the authors aim to delve into the dynamic of increased security and defense cooperation between the U.S. and Vietnam regarding the South China Sea issue from the beginning of Obama's presidency to the current Biden administration.The article seeks to address the question of whether the U.S. Vietnam bilateral cooperation is on an upward or downward trajectory, and, in the event that the partnership had fallen short of expectations, what specific roadblocks the two countries would have faced under each presidency.The first part of this article focuses on the U.S. security ties with Vietnam during the Obama administration's 2 four-year terms, suggesting that the bilateral relations have significantly improved, with a solid foundation being established for defense cooperation in the South China Sea.The second part examines the momentum of the maritime collaboration between the two countries over four years under the Trump presidency.The authors point out that despite the changes in the U.S. priorities in its regional outlook, particularly with Trump's U-turn of the engagement policy with China (Friedberg, 2022), the partnership between Hanoi and Washington achieved a new height in the ever-changing political landscape in the Indo-Pacific region.The third part outlines the significant developments of U.S. security ties with Vietnam during the first half of Biden's tenure.Given the current dynamics in U.S.-Vietnam relations, however, the authors argue it is far from certain that Washington and Hanoi would upgrade the bilateral relations to a strategic partnership in 2023-the 10th anniversary of their comprehensive partnership, which is solely based on the maritime security cooperation achievements.The authors advise further discussion on the prospects of the strategic partnership between the two countries, which could require greater efforts, including economic cooperation and people-to-people exchange from both Washington and Hanoi in the years to come.

U.S.-Vietnam maritime security cooperation in the South China Sea under the Obama administration
Under the two terms of the Obama administration, U.S.-Vietnam relations grew strongly and positively in a broad range of facets, namely diplomatic, economic, people-to-people, and defense and security.The rapid changes in the political landscape in the Asia-Pacific region grabbed Washington's attention in the early days of President Obama, the first U.S. "Pacific president" (Lieberthal, 2011).The U.S. priorities in foreign policy tilted toward the Asia-Pacific region, given the regional political dynamics in the South China Sea and the growth momentum of China.In fact, under the Obama administration, the U.S. adjusted its security strategy for the Asia-Pacific region given the regional geopolitical dynamics, with Washington promoting its policy of a "Pivot" in 2011, and then "Rebalancing" in 2012, toward Asia (Liu, 2020).Accordingly, the U.S. approach included its commitment to strengthening the military presence and fostering defense cooperation in the region, as well as maintaining regional affairs engagement through multilateral and bilateral frameworks.Obama's "Pivot" to Asia involved deepening commitments with regional allies, namely Japan, South Korea, Australia and the Philippines, and strengthening partnerships with Southeast Asian nations, including Vietnam (Fly, 2018).
To institutionalize bilateral partnerships between Vietnam and the U.S., leaders of the two countries agreed to level their ties up to a "comprehensive partnership" in 2013.This rank, despite being the lowest level according to Vietnam's diplomatic hierarchy, reflected a long-decade joint effort by the two sides in reconciling their ties from two former foes to promising partners.On security cooperation, because this is a very sensitive topic in overall bilateral ties, the Obama administration has skillfully navigated differences with Vietnam while striving slowly and cautiously to step up their cooperation.
Security cooperation between Vietnam and the U.S. gained meaningful achievements during Obama's presidency.Vietnam quickly became one of the only three countries in Southeast Asia that saw an increase in U.S. defense assistance (T.H. Le, 2017).The two countries sought to enhance ties, focusing on non-traditional security, such as military medicine, counter-terrorism, transnational crime, and maritime security, among others.The initiatives helped improve mutual understanding and strategic trust between the two countries, laying out solid foundations for the U.S.-Vietnam partnership in the years to come.In particular, maritime cooperation in the South China Sea was among the prioritized aspects that spearheaded bilateral joint efforts.
To a certain extent, shared concerns about China's growing clout in the region appear to be a significant and mostly unacknowledged factor bringing Vietnam and the U.S. closer together (T.H. Le, 2017).At the time, China was viewed as a future superpower in contemporary affairs, given its enormous population, rapid economic expansion, and significant military expenditure (Bellacqua, 2012).Hanoi and Washington have complex relationships with Beijing and stakeholders who militate against strategic clarity on the most salient issue they face-the rise of Chinese power.
China's expanding presence in the South China Sea has been a source of concern in the eyes of regional countries.Beijing's hegemonic ambitions are meant to challenge Washington's position in the region and displace the U.S.-led order, particularly in East Asia.In this regard, Vietnam and the U.S. have confronted a range of novel issues as a result of China's explosive economic growth, the global race for rare natural resources, and the quickening pace and wide-ranging nature of military modernization (Bellacqua, 2012).
The Obama administration made it plain that it will not only refrain from interfering in the South China Sea disputes but also prevent any nation from emerging to dominate the region and endanger U.S. interests.In identifying that the maritime territorial disputes in Southeast Asia considerably affect the economic interests and freedom of navigation of the U.S, the Obama administration made a significant effort to engage in the South China Sea (Cossa et al., 2009), as well as maintaining its position in the region through both military and non-military activities.
Although the U.S. is not a claimant state in the South China Sea, Washington has closely engaged with regional countries via (1) calling for an amicable resolution to promote regional stability, economy, and security, (2) objecting to any state using force or threatening to use force to enforce its national claim on the South China Sea, (3) prompting to help in a peaceful resolution of conflicting claims if requested by the parties and takes no opinion on the legal legitimacy of opposing sovereignty claims, and (4) affirming the stance of the importance of challenging any claims to the seas and islands outside of those covered by the United Nations Convention on the Law of the Sea (UNCLOS) 1982 (Christensen, 2006).
Earlier, the Hanoi Declaration made by U.S. Secretary of State Hillary Clinton at the ASEAN Regional Forum (ARF) on 23 July 2010, was a clear reflection of the Obama administration's stance on the South China Sea issue.In her "turning point" speech, Clinton highlighted the U.S. national interest in freedom of navigation and open access to Asia's maritime commons, citing that "the United States supports a collaborative diplomatic process by all claimants for resolving the various territorial disputes without coercion.We oppose the use or threat of force by any claimant.While the United States does not take sides on the competing territorial disputes over land features in the South China Sea, we believe claimants should pursue their territorial claims and accompanying rights to maritime space in accordance with the UN convention on the law of the sea.Consistent with customary international law, legitimate claims to maritime space in the South China Sea should be derived solely from legitimate claims to land features" (Clinton, 2010).
The U.S. posture could be read as an unequivocal approach when it comes to highly contentious tensions between a rising China on one side and U.S. allies, namely the Philippines, and regional partners, i.e.Vietnam, on another side.In the eyes of regional tiers, the U.S. stance, which indicated its intention to participate in the regional agenda, helped leverage the credibility of Washington and strengthen its prominence in the regional order.More importantly, Hanoi might find it possible to count on Washington to maintain its national interests in the face of Beijing's increasing ambition.

U.S.-Vietnam defense cooperation in the South China Sea under the Obama administration (2009-2017)
The first year of the term was marked by many visits of the two countries' officials, with personnel in both diplomatic and defense branches.In  Nguyen, 2019) in December.Exchanges between high-level officials of Hanoi and Washington even became "almost common, if not routine," reflecting a positive trajectory of the bilateral relations of the two former wartime enemies (Seth, 2010).
The two countries also engaged in several high-level bilateral dialogues on security issues, helping to advance security and defense ties, enhance mutual trust, and serve as a forum to handle divergence between the U.S. and Vietnam.Two prominent annual dialogues between Vietnam and the U.S., among others, are the vice-ministerial level Political, Security, and Defense Dialogue that kicked off in 2008, and the Defense Policy Dialogue conducted since 2010.In 2011, Hanoi and Washington agreed to high-level frequent defense discussions, collaboration in maritime security, as well as cooperation in peacekeeping, humanitarian aid, and disaster relief in a Memorandum of Understanding on Advancing Bilateral Defense Cooperation (T.H. Le, 2017).
The Hanoi-Washington security relationship, which has been built on mutual trust, understanding, and respect for independence and sovereignty, was highlighted by the military policy conversation as a turning point.The two countries repeatedly affirmed their intention to foster bilateral cooperation concerning international and regional security changes, which represents the maturity of U.S.-Vietnam ties in terms of political, economic, cultural, and social aspects (Office of the Spokesperson, 2011).In 2010, Vietnam had the first joint naval exercise 1 with the U.S., even though it was only on a small scale, including the first non-war cooperative training program to commemorate the 15th anniversary of the normalization of diplomatic relations (1995-2010) (D. C. Tu & Nguyen, 2019).In the same year, the U.S. Defense Secretary Robert Gates visited the Cam Ranh port for the first time since the Vietnam War (Yen, 2021).Robert Gates opened an Office of Defense Cooperation at the U.S. Embassy in Hanoi during that trip.The largest naval exercise in history, the Rim of the Pacific Exercise (RIMPAC-2012), welcomed Vietnam as an observer.
The U.S. Secretary of Defense Leon Panetta declared that the U.S. would relocate the majority of its naval force to the Pacific by 2020 and saw it as a component of a new strategy centered on Asia on 2 June 2012, at the Shangri-La Strategic Dialogue in Singapore (Alexander, 2012b).Following this strategy, the U.S. will change the proportion of naval forces stationed in the Pacific and Atlantic Oceans from 50-50 to 60-40, giving the Pacific region precedence (D. C. Tu & Nguyen, 2019).In June 2012, Defense Secretary Leon E. Panetta visited the USNS Richard E. Byrd vessel, which was anchored during repairs in Cam Ranh Bay, he stated that the U.S. could work with partners, including Vietnam, to be able to use the such harbor as part of the deployment of its ships in the Pacific (Alexander, 2012a)."Access for U.S. naval ships into this facility is a key component of this relationship and we see a tremendous potential here," and "we've come a long way, particularly with regards to our defense relationship," he said (Wan, 2012). 2 Technical assurance activities, especially the high-tech service of technical assurance for the Navy, are crucial to current military operations.Consequently, the Cam Ranh port would play a significant role in providing technological services, thanks to its inherent strategic advantages, not only for the People's Army of Vietnam but also for the warships of other nations with which Vietnam has diplomatic ties (Ton, 2018).It was the most senior U.S. official's visit to Cam Ranh Bay since the Vietnam War ended.Panetta's stopover was considered a crucial step in both sides' increasing militarization, which paved the way to deepen bilateral military ties based on the Memorandum of Understanding (MOU) on the military cooperation established in 2011.This agreement underlined the goal of strengthening training cooperation and expanding military practical collaboration with a focus on five priority topics, including cooperation in marine security, search and rescue, United Nations Peacekeeping Operations (UNPKO), humanitarian and disaster relief (HADR), and cooperation with defense institutions and research institutes (Embassy of the Socialist Republic of Vietnam in the United States of America, n.d.) In 2014, as the U.S. faced challenges to navigate its resources in the ongoing chaos in the Middle East (Roberts, 2017), the Asia-Pacific region became Washington's top priority in Obama's second term (Indyk, 2013).The U.S. strategic shift in foreign policy has been widely regarded as a reaction to China's regional economic and military muscle-flexing, particularly in the South China Sea (Petty & Rampton, 2016).According to M. Taylor Fravel, an associate professor of political science and a member of the Massachusetts Institute of Technology's Security Studies Program, there have been two key reasons driving the U.S. interests in the South China Sea.First, China threatened U.S. oil and gas businesses operating off the coast of Vietnam in 2007, signaling a threat to the U.S. and its corporations' marine commercial interests (Hayton, 2018;WikiLeaks, 2009).Second, China blocked the USNS Impeccable and naval survey ships of the U.S. in 2009, raising concerns about China's aggressive approach to freedom of navigation in international waters (Fravel, 2014).
The Obama administration has paid special attention to the issue of military-security cooperation in the region, with an aim of actively engaging in the South China Sea.Within six years, the maritime cooperation between Washington and Hanoi witnessed significant growth, transforming from port visits to multi-day engagements, which was titled Naval Engagement Activity (NEA) in March 2015.The non-combatant activities and expertise sharing in military medicine, search and rescue, and other areas are the main focus of this collaboration (U.S. Embassy and Consulate in Vietnam, 2015).The U.S. has taken a more active role in engaging in international security mechanisms and forums, such as the ASEAN Regional Forum (ARF) and the ASEAN Defense Ministers' Meeting-Plus (ADMM-Plus).In particular, the South China Sea issue was effectively addressed by the U.S. during ASEAN-led platforms.The efforts helped strengthen regional security, and build trust among regional countries, particularly competing claimants in the South China Sea.To the U.S., embracing multilateralism to deal with regional challenges would enable the nation to perform a two-fold strategy, namely promoting its leadership and influence in the region, and laying the groundwork for blocking China's escalating advance.
The U.S. was also proactive in putting out proposals to improve bilateral and multilateral ties with littoral nations in the South China Sea.In addition to the Philippines and its treaty allies, the U.S. also strengthens security ties with regional partners, namely Vietnam and Malaysia.In an analysis of the Obama administration's "pivot" strategy, Ian Nikolaevna Martynov, an expert at the Ural Institute for International Finance and Research, analyzed the foreign policy of the Obama administration to include the content of tightening capital alliances and developing U.S. new strategic partnerships (Trinh Thai, 2013).In the case of Vietnam, the convergence of strategic interests of the U.S. and Vietnam in the South China Sea propelled the two nations' security cooperation forward quickly (Shoji, 2018).In other words, maritime tensions in the South China Sea have played a major role in determining how Hanoi's and Washington's strategic interests converged (Thayer, 2018).Despite ongoing difficulties, the two nations have made great progress in strengthening defense ties.In a visit by U.S. Secretary of State John Kerry to Vietnam in December 2013, the U.S. offered new financial assistance of up to $18 million to Vietnam to strengthen maritime security along its shore, in particular, to enhance coastal patrols to aid in disaster response and search and rescue operations, as regional tensions with China over territorial claims in the South China Sea rise (Wroughton, 2013).
Since China moved its HD-981 Oil Rig close to Paracel Island in 2014, the South China Sea has become a flashpoint.China's resumed forays and aggressive actions into the South China Sea propelled Vietnam's security cooperation with the U.S. When President Obama visited Vietnam in May 2016, the U.S. government totally lifted the arms embargo on Vietnam.This gesture indicated the U.S. readiness to enhance its collaboration with Vietnam on maritime security.Another sign of improved military relations in U.S.-Vietnam ties is the U.S. Navy's regular port visits to Vietnam (D. C. Tu & Nguyen, 2019).Additionally, the U.S. increased its support for maritime security capacity building.Both countries signed the U.S.-Vietnam Joint Vision Statement on Defense Relations in June 2015.The Statement calls for intensifying bilateral cooperation on the South China Sea issue, citing, for instance, increased cooperation on maritime security and maritime domain awareness (MDA), including port visits and naval vessel journey repair visits to ports (Shoji, 2018).In May 2014, Vietnam joined the Proliferation Security Initiative (PSI), an initiative started by the U.S. with the goal of preventing the spread of weapons of mass destruction (U.S Embassy and Consulate in Vietnam, 2014).
In addition to promoting the military alliance cooperation mechanism, the U.S. has increased its support to regional countries, including Vietnam, regarding issues of military aid, weapons supply, patrolling, maritime security cooperation and information exchange.In 2015, U.S. Secretary of Defense Ashton Carter at the Shangri-La Dialogue announced the US$425 million Southeast Asia Maritime Security Initiative for maritime building efforts for partners in the region.Accordingly, this initiative is a new attempt to collaborate with U.S. allies and partners in Southeast Asia to create a shared maritime sector awareness infrastructure that will assist nations in information sharing, threat identification, and cooperative problem-solving (U.S. Embassy and Consulates in Indonesia, n.d..).Hence, Indonesia, Malaysia, the Philippines, Thailand, and Vietnam would be supported in providing equipment, consulting, training and small-scale military construction (Mehta, 2015).The U.S. sought to enhance cooperation with regional nations to pursue a broad range of goals, namely enabling effective maritime operations, and identifying new system requirements for essential security capabilities (Department of Defense, 2015).Building the Vietnam Coast Guard's capacities and performance has been among the priorities of collaboration in marine security between Vietnam and the U.S.
To Vietnam, the U.S. was no longer an enemy but rather a potential partner.The change indicated that Hanoi had become aware of how closely its strategic interests converged with those of the U.S. (Thayer, 2018).Vietnam and the U.S. can be prospective security partners despite several restrictions on their relationship, including lingering memories of the Vietnam War, the China factor, and ambiguity around American pledges (Shoji, 2018).Both sides benefit from close ties with each other.Given China's growing assertiveness in the South China Sea and Vietnam's high economic dependency on China, strong ties with Washington have served as an important part of Hanoi's hedging strategy in dealing with Beijing, reflecting its traditional statecraft in managing relations with other major powers (B.Tran & Sato, 2018).For Vietnam, strengthened defense relations with the U.S. can better Vietnam with regard to security.Furthermore, Hanoi may improve its standing in international affairs by maintaining a strong relationship with Washington (B.T. Tran, 2019).
However, given that both Hanoi and Washington have consistently stressed that territorial disputes should be resolved peacefully, these new advancements in maritime cooperation between the two nations should not be interpreted as just a response to China's increasing aggression in the South China Sea (D. C. Tu & Nguyen, 2019).Although the strategic goals of the U.S. and Vietnam in terms of defense and security cooperation are convergent, they are not congruent.With a defense policy of "three no's"-no alliances, no foreign bases, and no joining a second country to gang up on a third country, Vietnam does not want to be lured into the orbit of any major power.For instance, Vietnam may have quietly applauded the formation of the Quadrilateral Security Dialogue, but it is unsure that Vietnam would join the Quad (Thayer, 2018).
For its part, Hanoi appeared to win big in the enhanced ties with the U.S. In 2016, President Obama decided to announce the total annulment of the ban on lethal weapons sales to guarantee that Vietnam has access to the military equipment needed to enhance its defense capability (Harris, 2016).Theoretically speaking, it allowed Vietnam to expand its military sources and helped the U.S. to start a new chapter in geostrategic relations in the Asia-Pacific (T.H. Le, 2017).For Hanoi, the military ties with the U.S. were not previously regarded until the decades-old ban was overturned, as it represented a lack of trust from Washington despite normalization in 1995 (Hiebert et al., 2014).Although specific requirements on equipment sales to Vietnam remain, the U.S. decision highlighted the growing bonds between the two countries, enabling Washington to provide Hanoi with more weapons to enhance its defense (Parameswaran, 2016a).The decision was taken as U.S. defense suppliers could provide Vietnam's expanding demand for surveillance equipment like marine patrol and reconnaissance aircraft and command and control technology.
Nevertheless, the developmental trajectory of U.S.-Vietnam cooperation in the security sphere did not happen as smoothly as expected.It should be noted that Vietnam and the U.S. followed different pathways in efforts of enhancing bilateral relations, given that Washington sought access to ports for its military vessels on the Vietnamese coast, while Hanoi wanted a lift from Washington's arms sale restrictions (Jordan et al., 2012).Furthermore, Vietnam was also reluctant to engage with the U.S. joint exercises, signaling a sense of caution from Vietnam's side due to fears of angering China.For example, Vietnam rejected to observe P8 Poseidon maritime patrols over the South China Sea and decided not to participate in US-led CARAT (Cooperation Afloat Readiness and Training) exercises (T.H. Le, 2017).

U.S.-Vietnam maritime security cooperation in the South China Sea under the Trump administration (2017-2021)
The strategic ties between the U.S. and Vietnam have continued to flourish despite the skepticism of the U.S. role and commitments towards the Indo-Pacific region (Taylor, 2017), which had been sparked in the early days of President Trump's signature "American First" in the U.S. foreign policy footprint.As a result, the two countries increasingly saw one another as emerging partners in their strategic calculations and policies.Particularly, Washington's security cooperation with Vietnam under Trump's presidency has witnessed positive steps.In his 2018 visit to Vietnam, then-Secretary of Defense James Mattis called Hanoi and Washington "like-minded partners" that hold a forward-looking partnership (Lisa, 2018).The closer security ties between the two countries were mainly based on a growing convergence of strategic interests and priorities as well as shared concerns over China's increasingly aggressive stance on the South China Sea.
With the adoption of the "Free and Open Indo-Pacific" (FOIP) strategy in late 2017, the Trump administration has laid out a vision for engagement in the region, solidifying the U.S. presence and leverage against China's rising power.Trump's FOIP was a firm and robust commitment of the administration to the region.In his remark at the 2017 Asia-Pacific Economic Cooperation meeting (APEC) in Vietnam, Trump stridently articulated that the U.S. was eager to make "a renewed partnership with America to work together to strengthen the bonds of friendship and commerce between all of the nations of the Indo-Pacific, and together, to promote our prosperity and security" (Office of the Press Secretary, 2017).Principles of U.S. FOIP composed of (1) Respect for sovereignty and independence of all nations; (2) Peaceful resolution of disputes; (3) Free, fair, and reciprocal trade based on open investment, transparent agreements, and connectivity; and, (4) Adherence to international rules and norms, including those of freedom of navigation and overflight (Department of Defence, 2019).On the security aspect, as stated by Defense Secretary James Mattis at the Plenary Session of the Shangri-La Dialogue in 2018, the Indo-Pacific strategy was considered "a subset of our broader security strategy, codifying our principles as America continues to look West in which Washington sees deepening alliances and partnerships as a priority", including Vietnam (Department of Defence, 2018).It is noteworthy that maritime security was put on the top list of U.S. Indo-Pacific strategy for the security domain.According to Mattis, Washington would attach great importance to maritime space in the Indo-Pacific by supporting regional partners to strengthen their naval capabilities.
Against this backdrop, Trump's America has intrinsically positioned Vietnam as an emerging partner in the Indo-Pacific theater through an array of strategic documents, given Hanoi's geostrategic importance.In its 2017 National Security Strategy (NSS), the U.S. publicly stated that Vietnam-along with Indonesia, Malaysia, and Singapore-are its growing security and economic partners in Southeast Asia and vowed to help these countries become cooperative maritime states (The White House, 2017b).Meanwhile, the U.S. Department of Defense's National Defense Strategy of the United States of America, released in 2018, reported that Washington would fortify its ties with regional allies and partners, including Hanoi, in an attempt to build a "networked security architecture capable of deterring aggression, maintaining stability, and ensuring free access to common domains" (Department of Defence, 2018).Washington's prioritized security relationship has also been reaffirmed in the 2019 Indo-Pacific Strategy Report as emphasizing a focus on a "new relationship" with Vietnam to uphold peace and prosperity in the Indo-Pacific region.Accordingly, the report stated that the U.S. "is building a strategic partnership with Vietnam that is based on common interests and principles, including freedom of navigation, respect for a rulesbased order in accordance with international law, and recognition of national sovereignty" (Department of Defence, 2019).
Meanwhile, Hanoi has embraced its hedging playbook by moving toward a closer partnership with the U.S. to put a check on China's growing assertiveness in the South China Sea (Hanh Nguyen, 2020).Furthermore, Vietnam, while trying to keep its deliberately balancing act vis-à-vis great powers and avoid taking sides, was supposed to a certain extent to implicitly support the U.S. FOIP strategy (Grossman, 2020).From the Vietnamese point of view, some principles embodied in this strategy, such as rules-based order, the freedom from coercion, and the freedom of navigation and overflight, were seemingly compatible with Vietnam's national security interests (Hong Hiep, 2018), particularly in the face of looming China threat in the South China Sea.In other words, some scholars argued that Vietnam is utilizing the U.S. strategy's freedom of navigation and overflight, and the rule of law on the sea to counter China's increased belligerence in the South China Sea (Jung et al., 2021).For instance, the 2019 version of the Vietnamese Defense White Paper rarely mentioned the term Indo-Pacific, with an emphasis instead on that "Viet Nam is ready to participate in security and defense cooperation mechanisms suitable to its capabilities and interests, including security and defense mechanisms in the Indo-Pacific region" (Vietnam Ed., 2019).
Under the Trump administration, Washington and Hanoi have increasingly become more convergent on their views about China's perpetual assertiveness and hegemonic ambition in the South China Sea.During Trump's term, Beijing hardened its assertive policy to intimidate other claimants in the South China Sea, stirring up tensions with Vietnam in these contested waters.For example, the Chinese survey vessel of Haiyang Dizhi 8 intruded the Vietnamese Exclusive Economic Zone (EEZ) in 2019 posed enormous challenges for Hanoi in terms of legal, diplomatic, and economic aspects (Huong, 2019).It was reminiscent of the HYSY-981 oil rig crisis in 2014, which triggered anti-China protests across Vietnam's provinces and cities.Another example is, at the time when the international community wrestled with the COVID-19 pandemic, Beijing took this opportunity to scale up its influence and aggressive posture in the waters such as the sinking of a Vietnamese fishing vessel near the Paracel Islands and unilaterally establishing the so-called two new administrative districts to manage the disputed Paracel and Spratly Islands that are also claimed by Vietnam (Huynh, 2020a).In contrast to the previous administration's deliberate engagement with China, the Trump administration has taken a tougher stance toward Beijing, asserting that "the old paradigm of blind engagement with China simply won't get it done" (Office of the Spokesperson, 2020b).The U.S. flatly labeled China as the "revisionist power" and the "strategic competitor" who sought to blunt the U.S. influence of power in the Indo-Pacific and restructure regional order in Beijing's favor (Department of Defence, 2018; The White House, 2017b), and that "the Indo-Pacific increasingly is confronted with a more confident and assertive China that is willing to accept friction in the pursuit of a more expansive set of political, economic, and security interests" (Department of Defence, 2019).
Concerning the South China Sea issue, the U.S. has been a more vocal critic of China's assertiveness in these waters.The NSS warned that Chinese militarization behaviors in these disputed waters "endanger the free flow of trade, threaten the sovereignty of other nations, and undermine regional stability".Furthermore, in a move signaling the U.S. shifting position in the maritime disputes of the South China Sea, US Secretary of State Mike Pompeo in July 2020 issued a statement explicitly rejecting China's ill-evidenced maritime claims and its bellicose behaviors in the South China Sea, voicing support for others regional claimants.Accordingly, Washington "rejects any PRC claim to waters beyond a 12-nautical mile territorial sea derived from islands it claims in the Spratly Islands (without prejudice to other states' sovereignty claims over such islands).As such, the U.S. rejects any PRC maritime claim in the waters surrounding Vanguard Bank (off Vietnam), Luconia Shoals (off Malaysia), waters in Brunei's EEZ, and Natuna Besar (off Indonesia), and Chinese actions "to harass other states' fishing or hydrocarbon development in these waters-or to carry out such activities unilaterally-is unlawful" (Michael, 2020).This bold stance-in turn, might be a triumph for Vietnam, as Hanoi has taken a long way to internationalize the disputed waters.In response, Vietnam stated it "welcomes countries' positions on the East Sea issues which are consistent with international law and share the view, as stated in the statement issued on the occasion of the 36th ASEAN Summit, that the UNCLOS [United Nations Convention on the Law of the Sea] sets out the legal framework within which all activities in the oceans and seas must be carried out" (Vietnam Ministry of Foreign Affairs, 2020).
Having highlighted concerns about China's intensifying aggressiveness in the South China Sea and its ambitions to control these waters, Vietnam and the U.S. were keen on advancing their ties in the maritime security domain.The unprecedentedly wide-ranging cooperation included increasing high-level exchanges, military assistance, historic visits of American aircraft carriers, and joint naval exercises.
One of the key elements to gauge the degree of closeness between the two countries is a flurry of bilateral high-level visits.During the Trump government, Washington and Hanoi have enjoyed a much closer engagement and interactions in terms of security cooperation than ever before.At the highest level, President Trump visited Vietnam twice in the year of 2017 and 2019 while Prime Minister Nguyen Xuan Phuc became the first leader in Southeast Asia to set foot in Trump's White House in 2017, just four months after Trump's inauguration.During visits, the two states' leaders expressed efforts to enhance maritime security cooperation, underlined the respect for freedom of navigation and overflight and the unwavering commitment to settle territorial disputes by peaceful solutions in accordance with international law.To further make U.S.-Vietnam defense ties more institutionalized, both sides, in their 2017 Joint Statement, approved the Plan of Action for United States-Vietnam Defense Cooperation for the period of 2018-2020 to implement the 2011 Memorandum of Understanding (MOU) on Advancing Bilateral Defense Cooperation as well as the 2015 Joint Vision Statement on Defense Relations (The White House, 2017a).Additionally, back-and-forth visits from two sides' senior defense officials-both official and sideline meetingsalso grew remarkably, contributing to enhancing mutual trust and understanding.For example, Trump's first defense secretary, Jim Mattis, visited Vietnam twice in January and October 2018the first sitting US defense chief to do so, while Defense Secretary Mark Esper, his second, had a trip to the country in 2019, in which he announced that Washington would transfer a second Hamilton-class High Endurance Cutter to Hanoi.Admiral Philip S. Davidson took his first visit to Vietnam as the 25th Commander of the U.S. Indo-Pacific Command (USINDOPACOM) (Prashanth, 2019).For its part, Defense Minister of Vietnam Ngo Xuan Lich visited the U.S. in 2017.Moreover, Vietnam and the U.S. maintained their security ties through Defense Policy Dialogue at the level of Deputy Minister as well as Political, Security, and Defense Dialogue.
Washington has consistently helped Vietnam in bolstering its maritime military capabilities and law enforcement.According to the factsheet "U.S. Security Cooperation With Vietnam" updated in 2021(Bureau of Political-Military Affairs, 2021), in the fiscal year 2017-2021, Vietnam already received roughly $60 million through the Foreign Military Financing (FMF) program and over $20 million under the U.S.-led Southeast Asia Maritime Security Initiative.Hanoi was also funded with $81.5 million via the Foreign Military Financing program to support the Indo-Pacific Strategy through the fiscal year 2018 alone.To be specific, through these security assistance initiatives, the Trump administration transferred the first former-Hamilton class coast guard cutters in 2017 to the Vietnamese Coast Guard under the Excess Defense Articles program, allowing Hanoi to better protect its maritime sovereignty and counter Chinese expansion in the South China Sea.At the same time, USCG spokesperson Lt. Scott Carr praised this transfer as it helped to reinforce the partnership between the two countries' Coast Guard agencies, enhance interoperability, and bolster maritime governance in a free and open Indo-Pacific (Tom, 2021).Additionally, between 2017 and 2020, Vietnam received a total of 24 45-foot Metal Shark patrol boats, which significantly strengthened Hanoi's military strength in many aspects, such as anti-piracy, maritime law enforcement, maritime search and rescue, and maritime humanitarian assistance operations (D. C. Tu & Nguyen, 2019), in the face of Chinese increasing provocations in the South China Sea.Through FMF, Vietnam also purchased unmanned aerial systems (UAS), and coastal radars for its effort to strengthen maritime domain awareness (Suh Jung, 2020).
After the U.S. considered to provide Vietnam with trainer aircrafts and other equipment as Secretary Mattis claimed in 2018 (Trong, 2018), Hanoi joined in training on military aircraft through the U.S.-funded Aviation Leadership Program and had the first-ever air force pilots completed this training course in 2019 (H.Nguyen, 2019).That said, this sort of training would help to strengthen the bilateral security cooperation between the U.S. and Vietnam.
Regular port calls and jointly multilateral exercises were also indicators of deepened maritime cooperation between Vietnam and the U.S. Hanoi also took part in the U.S.-led Rim of the Pacific (RIMPAC) exercises-the world's largest multinational maritime exercise-in 2018 after being an observer in 2012 and 2016.Remarkably, during the Trump administration, Washington has successfully conducted its aircraft carrier's first-ever visits to a Vietnamese port, marking a new height of strategic ties between the two former adversaries.In March 2018, USS Carl Vinson made a landmark port call to the central city of Danang (Carl Vinson Strike Group Public Affairs, 2018).This unprecedented visit was highly significant not simply because it was the first time the U.S. sent a carrier to Vietnam since the end of the Vietnam War in 1975.More importantly, the visit supposedly served as part of a reconciliation process between the former foes, demonstrating long-standing commitments of the U.S.-Vietnam partnerships, particularly with steady advancements in maritime security cooperation (Jonathan & Marston, 2018).The 2018 visit of USS Carl Vinson was followed by the five-day visit of the USS Theodore Roosevelt to the same port in March 2020, indicating yet another breakthrough of a closer security partnership.It would be noted that the second U.S. aircraft carrier to Vietnam was among a series of events celebrating the 25th anniversary of the normalization of diplomatic relations between the U.S. and Vietnam.This move was indicative of the most visibly symbolic gesture for the deepening ties between the two states.In the words of the U.S. ambassador to Vietnam Daniel Kritenbrink, these ports of call "not only strengthen the United States' partnership with Vietnam, but they also continue to ensure peace and stability and freedom of commerce" across the Indo-Pacific region (Reuters Staff, 2020).Strategically, although US port calls did not occur regularly or annually during Trump's four-year tenure, it appears that the recently rising navy-to-navy bonds between the two countries reflected from such visits were profound amid mounting U.S.-China rivalry and China's growing aggressive behaviors in the South China Sea.As put aptly by Le Hong Hiep-senior fellow at Singapore-based ISEAS-Yusof Ishak Institute, the visits not only demonstrated Vietnam's desire to pursue longterm strategic ties with the U.S. as long as a such partnership was beneficial to Hanoi's national interests, but also showcased Hanoi's willingness to take bold actions to push back against China if Beijing increased its coercive activities in the region (Le Hong, 2020).
By overcoming suspicion and uncertainties about Trump's policy towards the Indo-Pacific in general and the U.S.-Vietnam relations, Vietnam has kept a quietly positive momentum in security cooperation on the South China Sea with the U.S.-a hard task for Hanoi's deliberate balance policy vis-à-vis great powers.Mutual interests, perceptions of a free, stable and prosperous Indo-Pacific, and lingering concerns over China's growing assertiveness in the South China Sea are among notable factors pushing Vietnam and the U.S. more closely than before.
However, despite some progress made during the Trump's presidency on maritime security cooperation between the U.S. and Vietnam in the South China Sea, impediments still existed and necessarily upset the looking-forward relations of the two countries.For instance, in response to the U.S. pressure Vietnam to comply the Countering America's Adversaries Through Sanctions Act (CAATSA), which was passed in 2017 to sanction countries seeking to buy Russian military equipment, Hanoi subtly canceled 15 defense engagement activities with Washington for 2019 (Thayer, 2022).Hanoi's move was partly seen as a bargaining tactic to press Washington to address this matter (Le Hong, 2018), as well as a response to the Trump administration, which privately pressed Hanoi to reduce its reliance on Russian armaments and instead acquire US weapons (Thayer, 2022).Besides, it is worth to note that as mentioned above on, there was no major arms sale made between Vietnam and Trump's America since the lift of the embargo on lethal weapons.

The U.S.-Vietnam maritime security cooperation in the South China Sea under the Biden administration (2021-present)
The U.S.-Vietnam relations under Biden's presidency have seemingly aligned with the stable trajectory of the ties in recent years, particularly under the administrations of Obama and Trump.Growing bonds between Hanoi and Washington have been expanded in a broad range of aspects, such as trade, culture, people-to-people exchange, and defense.More importantly, the maturity of U.S.-Vietnam relations has been headed toward a new height as the two countries approach the 10th anniversary of the comprehensive partnership in 2023.According to Nguyen Quoc Dung, Vietnamese Ambassador to the U.S., bilateral relations have gained momentum with considerable milestones demonstrating the comprehensive cooperation of the two countries (Vietnam News Agency, 2022a).In turn, while U.S. Ambassador to Vietnam Marc Knapper stated that the relationship between the two nations, which was developing in all aspects, was approaching a tipping point (Thuong, 2022), U.S. Visiting Assistant Secretary of State for East Asian and Pacific Affairs Daniel Kritenbrink later expressed optimism about the U.S.-Vietnam relations, calling it "stronger than ever" (Vietnam News Agency, 2022c).
In terms of strategic policy stance, Washington under the Biden administration has constantly recognized Hanoi's significance.It should be noted that Vietnam was one of the only two Southeast Asian countries officially mentioned in the U.S. Interim National Security Strategic Guidance issued in early March 2021 (Biden, 2021).Washington stated that it would foster relations with Hanoi, in addition to India, New Zealand, Singapore, and other Association of Southeast Asian Nations (ASEAN) countries, to "advance shared objectives'' (The White House, 2021).In the Indo-Pacific Strategy released in February 2022, the U.S. continuously mentioned Hanoi as one of its "leading regional partners" with whom Washington would seek to strengthen relations (The White House, 2022a).The Biden administration particularly reaffirmed its commitment to offer security support to the regional nations in terms of enhancing maritime capacity and maritime-domain awareness, citing Washington's aims to create a free and open region that featured connectivity, prosperity, security, and resilience.
Washington's clear-cut orientations are embraced by its regional allies and partners, including Vietnam.For Southeast Asian nations, maritime issues, including trade, transport, smuggling, and human trafficking, among others, have long been a particular source of concern.Previously, ASEAN made efforts to address maritime security as one of its key threats with the launches of the ASEAN Maritime Forum in 2003 and the Expanded ASEAN Maritime Forum in 2012 (Krishnan, 2022).For Vietnam, particularly, by framing the extent of the partnership expansion, Washington has highlighted priorities in bilateral relations, with maritime cooperation being viewed as one of the pillars of the two countries' joint efforts.Given the importance of Vietnam in the U.S. Outlook toward the Indo-Pacific region, Washington has demonstrated its ambitions to put words into action, with an aim of upgrading the bilateral partnership to a new height.
In Vietnam, there has appeared an absence of a concrete maritime security conceptualization in official documents (N.D. Nguyen, 2021).Hanoi has underlined its profound comprehension of the issues during its officials' political discourse.During the remarks delivered at the United Nations Security Council High-level Open Debate under the theme of "Enhancing Maritime Security-A Case for International Cooperation'' in August 2021, Prime Minister Pham Minh Chinh stated that cooperation on enhancing maritime security had been a must of the international community, citing both traditional and non-traditional security challenges, namely terrorism, climate change, marine environment pollution, and escalated tensions caused by unilateral acts violating international law (Vietnam News Agency, 2021a).The statement of the head of the Vietnamese government came after the ASEAN-US Special Summit held on 13 May 2022, in which Prime Minister Chinh welcomed the U.S. initiatives to strengthen maritime cooperation with the region (Vietnam News Agency, 2022b).
In the eyes of Vietnam, strengthening relations with Washington allows Hanoi to fuel the national socio-economic growth by drawing on U.S. expertise and capability in terms of technology, governance, and macroeconomic management, among others.More importantly, by doing so, Vietnam could leverage its image in the international and regional fora, which serves as part of an overarching effort of Vietnam's statecraft to preserve national interests.Given China's assertive behaviors in the region, particularly in the South China Sea, a growing partnership between Vietnam and the U.S. could provide Hanoi with courage and determination, in addition to the material and financial resources from Washington, in pursuing its strategy to settle long-term maritime territorial quarrels with the northern neighbor.
In efforts to garner U.S. support, Vietnam has also sought to put a check on China's growing assertiveness in the South China Sea.In March 2021, two months after the inauguration of President Biden, the incursion of some 200 Chinese vessels in the Whitsun Reef raised concerns among regional states and sparked strong objections from Hanoi and Manila (Linh, 2021).Although Vietnam has demonstrated its unwavering stance in safeguarding its sovereignty claimed in the South China Sea, it appears that Hanoi could not solely count on its will to deal with Beijing's coercive actions in the region.In this regard, Vietnam finds it possible to foster bilateral ties with the U.S., given that Washington could provide Hanoi with both political and practical support.Improving relations with the U.S., in maritime aspects particularly, has mirrored a nuanced response of Hanoi in the face of the Chinese clout in the region.For Vietnam and other regional countries, as long as China continues to use intimidation to fulfill its hegemonic ambition in the region, Washington's maritime support for ASEAN nations, including Vietnam, remains crucial, and its presence in the region appears to be irreplaceable, given that Hanoi and other ASEAN countries are more minimally equipped than Beijing both economically and militarily.
Hanoi and Washington have consistently sought to keep words and deeds aligned, while gradually building up trust and confidence in the relationships.In terms of the bilateral security sphere, Vietnam and the U.S. have taken part in up to 11 political, security, and defense dialogues to address maritime security, humanitarian assistance and disaster relief (HADR), and peacekeeping operations, among others (Bureau Of East Asian And Pacific Affairs, 2022).
The talks, first of which was held in 2008, regularly cover a broad range of aspects and address the shared concerns in terms of political, security and defense in the bilateral relations (Embassy of the Socialist Republic of Vietnam in the United States of America, n.d.).The initiative is set to promote the ties between the two countries with the participants reflecting the diversity of the partnership within the two governments, including high-ranking representatives from Vietnamese Ministry of Foreign Affairs, Ministry of Public Security, and Ministry of National Defense, as well as U.S. peers from Department of State, Department of Defense, Agency for International Development, and the U.S. Pacific Command (C.Thayer, 2013).Based on the foundation of the inaugural dialogue in Hanoi in 2008 (Manyin, 2009), which is further solidified by the 2011 MOU and the 2015 joint vision statement on defense relation (Embassy of the Socialist Republic of Vietnam in the United States of America, n.d.), topics discussed in the agenda varies over the years, but frequently focusing on "security cooperation and defense trade; maritime security; peacekeeping [. ..] and humanitarian issues, including POW/MIA recovery and clearance of legacy unexploded munitions" (Office of the Spokesperson, 2020a).
The foundations provide Vietnam and the U.S. with flexible frameworks for the exchange of ideas and solutions, facilitating the partnership expansion at bilateral and multilateral levels.According to Vietnamese President Nguyen Xuan Phuc in September 2022, U.S.-Vietnam relations have grown "effectively, sustainably and mutually beneficially" after a quarter-century of normalization, based on the tenet of the two countries' respect for specific characteristics of each other, including independence, sovereignty, and political institutions (Vietnam News Agency, 2021b).
The recent high-profile officials' exchanges between Washington and Hanoi have strongly highlighted the two nations' commitment to the partnership.The visits have reflected the traditional conduct of diplomacy from both countries, which has been practiced over years under the administrations of Obama and Trump.In mid-2021, the Biden administration demonstrated its endeavors to engage in Southeast Asia, with both Secretary of Defense Lloyd Austin's trip in July and Vice President Kamala's visit in August choosing Singapore and Vietnam as destinations.In Hanoi, Secretary of Defense Austin addressed the key issues of bilateral ties, including COVID-19 cooperation and war legacy initiatives.Meanwhile, Harris's visit further underlined Washington's intention to foster relations with Hanoi by promising to support "Vietnam's enhancement of its maritime security and law enforcement capabilities" (The White House, 2021).It should be noted that Harris's visit to Vietnam was the first by a sitting U.S. vice president, which enhances the trip's significance and increases the message's credibility that she carried for the U.S. to the Southeast Asian country.
In the remarks at the Center for Strategic and International Studies, on the sideline of the visit to the U.S. to attend the Special ASEAN-U.S. Summit in May 2022, Prime Minister Pham Minh Chinh highlighted the foundations of "sincerity, trust, and a sense of responsibility" of the bilateral bonds with an "extraordinary growth of the relationship between Vietnam and the U.S. in the three decades following normalization" (Center for Strategic and International Studies, 2022).In addition to other ASEAN members, Vietnam and the U.S. were committed to strengthening maritime cooperation through ASEAN-led mechanisms, namely ARF, ADMM-Plus, and EAS (The ASEAN Secretariat, 2022).The efforts enable Hanoi, Washington, and regional states to address the shared concerns in the maritime space, namely natural resource exploitation on the sea, smuggling, human trafficking, and transportation, with joint initiatives being proposed in the multinational frameworks.
With U.S. support through FMF activities, particularly in the fiscal years between 2017 and 2021, Washington has significantly increased Vietnam's maritime security capacity, strengthening Hanoi's defense with cutting-edge U.S. military equipment while solidifying Washington's posture in the Indo-Pacific region (Ordaniel, 2021).As Hanoi is seeking arms diversification and reducing reliance on Moscow's supplies, the U.S. has intended to support Vietnam's endeavor of modernizing its defense capability (Guarascio & Vu, 2022).In particular, the U.S. Coast Guard delivered the second vessel of the Hamilton-class cutter, CSB 8021, to the Vietnam Coast Guard under the U.S. Excess Defense Articles program in June 2021 (Minh, 2021).The first one, CSB-8020, was previously transferred to Vietnam in May 2017.In a similar vein, U.S. Ambassador to Vietnam Marc Knapper in April 2022 said that the third cutter was set to be transferred to Vietnam as part of efforts to strengthen Hanoi's military capability and intensify bilateral relations (Minh, 2022).
Arguably, U.S. tangible deliverables could help Hanoi accomplish the objectives as stated in the resolution on the national maritime strategy to 2030, with a vision to 2045, which was released in the 8th Plenum of the 12th Party Central Committee in 2018.The document underlined the ambition to make Vietnam "a strong maritime country, enriched by the sea, relying on and looking towards the sea" (Ta Quang Ngoc, 2018).However, since the lifting of the arms embargo under the Obama presidency in 2016, Washington has only delivered to Hanoi two naval cutters and two T-6 Texan trainer aircraft, with another 10 of which will be supplied by 2027 (Guarascio, 2022).Meanwhile, Hanoi has faced difficulty making new military deals from other countries, given the its limited budget for new items, notably Western countries' weaponry, and risks of the compatibility of between weapon equipment originated by Russian and non-Russian (Le Hong, 2022).
Concerns have remained in the eyes of Hanoi, given the impacts of its linkages with Russia toward the growing relations with the U.S. The arm deals between Vietnam and Russia may leave Hanoi highly subject to the CAATSA.To make the matter worse, the Russian invasion in its neighboring Ukraine is bound to cause a reduction in Russian arms sales to Southeast Asian nations, including Vietnam, given the pressures posed by Western countries' sanctions on Russia (Le Hong, 2022).Though former U.S. Secretary of Defense James Mattis made efforts for a waiver for Vietnam from Congress, in addition to India and Indonesia, there has been no final decision ever since (B.T. Tran, 2020).
By and large, U.S.-Vietnam relations have gained substantial momentum for roughly two years under the Biden administration, with opportunities for both countries to deepen the partnership still being ample.As stated by President Nguyen Xuan Phuc, the achievements have contributed to the tireless efforts of building trust from both sides (Vietnam News Agency, 2021b).However, challenges remain given the internal and external challenges of the ties, particularly with the impacts of China on the politics of the U.S.-China-Vietnam triangular relations.For Hanoi, Beijing is viewed as a close neighbor and an ideological comrade, while Washington is one of Vietnam's growing partners (Huynh, 2022).As China regards a growing connection between Vietnam and the U.S., particularly in defense cooperation aspects, as worrisome, Beijing has sought to maintain Hanoi's neutrality and reinforce the shared ideological bedrock of the two nations (Fischler, 2021).In this regard, given the heightened tensions of the Sino-U.S. rivalry, Vietnam has faced a looming threat of being caught in great power politics, and it has been left with little choice but to walk on a tightrope between the two superpowers.
Vietnam's prudent approach, however, has partially hindered Hanoi from fully embracing American engagement in the region and, to a certain extent, impeded the prospects for developing the partnership.Hanoi's lukewarm response to the U.S. regional outreach this year grabbed the intention of international relations scholars.In July 2022, USS Ronald Reagan was reportedly planning to visit Da Nang, marking the third biennial trip by a U.S. aircraft carrier to Vietnam following USS Carl Vinson in March 2018 and USS Theodore Roosevelt in March 2020 (RFA Staff, 2022).Still, the trip did not happen indeed.Although it was unclear about the reasons for the trip cancellation, experts doubted the impact of China on Hanoi's decision.B. T. Tran (B.T. Tran, 2022a) cited Thayer Consultancy that the suspension from the Vietnamese authorities was due to "concerns about a possible Chinese attack on Taiwan," considering the controversy surrounding Nancy Pelosi's possible visit to the archipelago at the time.In October 2018, Vietnam reportedly canceled 15 defense cooperation activities with the U.S. in terms of army, navy and air force exchanges scheduled for 2019, as sourced from a publication of Carlyle A. Thayer (Le Hong, 2018).Hanoi also did not send its force to participate in multinational littoral operations in the U.S.-led Rim of the Pacific (RIMPAC) exercise, the world's largest international maritime drill concluded on August 4. Previously, Vietnam sent observers to the RIMPAC in 2012 and 2016, and it participated in the exercise in 2018.Conceivably, given the escalating concerns following Pelosi's trip to Taiwan, which took place as planned sparked anger from China, Vietnam might find it difficult to welcome the U.S. carrier and join the drill, as it served as a chance to forge defense cooperation and practice interoperability capability with the U.S. and its 21 allies and partners, including Australia, Japan, Republic of Korea, and India, among others (Mahadzir, 2022).
For the U.S., signs of skepticism have become evident in the current trajectory of the U.S.-Vietnam bonds.In October 2022, the National Security Strategy left Vietnam out, despite stating Washington's efforts to work closely with regional nations, namely India, the Philippines, New Zealand, and Thailand (The White House, 2022b).Although the decision seems to be an unintentional move of Washington, it may raise some concerns for Vietnam as it is the first time that Hanoi has been absent from U.S. written policy frameworks for the region since the Biden administration began.
In 2023, Vietnam and the U.S. will celebrate the 10th anniversary of the comprehensive partnership.Among permanent members of the United Nations Security Council, Vietnam has comprehensive strategic partnerships with China and Russia, strategic partnerships with France and the United Kingdom, and a comprehensive partnership with the U.S. To Washington, it will be high time for the two countries to upgrade their relationship, which reflects the maturity of the bilateral bonds.Marc Evans Knapper, the U.S. ambassador to Vietnam, said that Washington prioritized raising the U.S.-Vietnam relations to a "strategic partnership" (Quynh & Huong, 2022).The U.S. intention has sent a message of goodwill from the Biden administration to Hanoi.The U.S. has sought deepened ties with Vietnam, given its increasing role in the region and the growing bonds between Hanoi and Washington.Previously, in the words of U.S. Assistant Secretary of State Daniel Kritenbrink, Vietnam played a central position in the Indo-Pacific strategy of Washington (Vinh & Linh, 2022).However, it is less likely that Washington and Hanoi could upgrade their partnership within 2023, given the U.S.-Vietnam relations dynamics and recent indications in Vietnam's political environment.Even though Hanoi stated that it was more important to focus on the substance of the ties, instead of their label, according to Ha Kim Ngoc, former Vietnamese ambassador to the U.S. (Thanh, 2020).Beijing appears to be the major source of concerns in Vietnam's current decisionmaking process, which is widely impacted by the conservative stance of VCP's General Secretary Nguyen Phu Trong.Indeed, the Politburo's General Secretary "sets the ideological tone for the Party," despite the hallmark of Vietnam's collective leadership (Abuza, 1997, p. 12).Vo Van Thuong, the youngest member of the VCP's Politburo and supposedly part of Secretary General Trong's inner circle, became the new Vietnam's president after an extraordinary session of the National Assembly on March 2 (Strangio, 2023).It came after the trip of Trong to China from October 30 to 2 November 2022, as the first foreign leader to visit China after the Chinese Communist Party's 20th Party Congress (H.Le, 2022).The timing, according to Nian Peng, "sends a strong signal that Vietnam is not going to side with the U.S. against China" (Peng, 2022).For Hanoi's leadership, any advancement in the bonds between Vietnam and the U.S. could distress China and make it harder for Hanoi's foreign affairs, including sanctions, cyber warfare, and maritime aggression in the South China Sea (Phuong, 2022).
A written joint statement will be the most desirable outcome of both sides' commitments (B.T. Tran, 2022b), although Vietnam and the U.S. has enjoyed a strategic partnership in all aspects of the notion, yet except the name, in the eyes of observers (Doan, 2019).Given the growing ties of the U.S.-Vietnam relations, prospects for the two countries to enhance the bilateral ties are here to stay, with priorities lying on maritime cooperation.Still, the upgrade calls for additional efforts to strengthen the mutual credibility of the partnership, particularly in terms of trade, cultural, and people-to-people cooperations beyond only the foundations of maritime cooperation operations between Vietnam and the U.S.More importantly, as long as China's influence on Vietnam's politics persists, any breakthrough in relations with the U.S. will remain uncertain.Washington's patience and sympathy for Hanoi's conundrum caught in the Sino-U.S. competition could last (Huynh, 2022), but for how much longer?Considering Hanoi's reluctant stance, Vietnam would be put in the dilemma of missing development chances with Washington, regardless of the flourishing trajectory that U.S.-Vietnam relations have enjoyed over the years.

Conclusion
Putting differences aside, the bilateral relationship between Vietnam and the U.S. has advanced significantly.In particular, defense and security cooperation between Vietnam and the U.S. has seen rapid growth, notably under the administrations of Obama, Trump, and Biden.Given the geopolitical opportunities and challenges in the Indo-Pacific region, U.S.-Vietnam relations are approaching a tipping point, in which the two countries will celebrate the 10th anniversary of their comprehensive partnership in 2023.
The bilateral cooperation is closely associated with the current state of the region, in which the importance of mutual stability and prosperity is widely underlined in the nation's political discourse.More importantly, the ties between Vietnam and the U.S. have been assumedly even more significant in light of the ever-changing regional landscape, with looming threats posed by a broad range of uncertainties, namely great power politics with the Sino-U.S. rivalry, the rise of authoritarianism given the Taiwan Strait crisis and the Russian war in Ukraine, and non-traditional security risks, i.e. climate change, diseases, transnational crime, pollution, and human trafficking, among others.Facing arduous challenges at home and abroad, Vietnam and the U.S. have been more determined to enhance bilateral relations through joint initiatives at both bilateral and multilateral levels.
Under the tenure of President Obama, the U.S. sought to relocate its resources to the Asia-Pacific with a focus on the South China Sea issue.In the eyes of the U.S., the region holds its essential maritime security interests and plays an important role in Washington's foreign policy.That being said, freedom of navigation has been regarded as a key element of its interests as well as the U.S. stances in the South China Sea.The evidence has been found in many political discourses by U.S. high-ranking officials, such as U.S. Secretary of State H. Clinton and Secretary of Defense Robert Gates.Accordingly, the maintenance of freedom of navigation was highlighted so as to ensure U.S. interests in the region, particularly with trade and security.It should be noted that the South China Sea area is featured by many contradictions and territorial disputes between China and its other claimants in the region, including Vietnam.To a certain extent, lingering issues over sovereignty have emerged as a source of concern to the U.S. As a result, in addition to voicing its stance of promoting peaceful solutions to these regional tensions that are in accordance with international law, the U.S. seeks to strengthen its support to its treaty allies and regional partners, including Vietnam.
Perceivably, Vietnam has become one of America's critical regional partners, and vice versa.When U.S. President Barack Obama decided to lift the lethal arms embargo imposed on Vietnam in 2016, the two countries saw a significant turning point in their bilateral security relations.The decision effectively eliminated the last policy barrier holding back bilateral relations, giving both sides more opportunities for cooperation.Through many U.S. presidential administrations, including those of Obama, Trump, and the current Biden administration, defense and security cooperation between the two nations has been maintained and developed to a more stable and flourishing trajectory.
For Vietnam, an environment of peace, stability, cooperation, and development in the region is of strategic importance.Thus, both Vietnam and the U.S. have found that there has been room for cooperation expansion, given the bilateral common interests and shared objectives.In other words, the growing strategic convergence of interests is a crucial factor that has promoted collaboration between Vietnam and the U.S., in which Hanoi and Washington have their own rationale to further reinforce the ties.
April 2009, representatives of Vietnam's Defense Ministry visited the USS John D. Stennis (CVN-74), an aircraft carrier patrolling in the South China Sea.Six months later, Secretary of Defense Robert M. Gates paid a trip to Vietnam, before his Vietnamese counterpart, Defense Minister Phung Quang Thanh, met U.S. Pacific Command (USPACOM) Commander Robert Willard in Hawaii on his way to Washington, D.C. (D. C. Tu &