The Containment of the Islamic State: A Realist Case to Engage a Hybrid Actor

Next to military means, causing disruption and interdiction, Western and local powers also relied on policies of containment to halt the expansion of the Islamic State’s territorial strongholds. Yet, a Cold War state-based strategy of containment seems not apt to counter a transformed Islamic State. This article, first, examines why containing the Islamic State was successful in the past. Second, the article argues that the Islamic State can still be contained if containment addresses the Islamic State’s hybrid nature rather than convulsively looking for the transferability of past containment aspects. In particular, this requires a focus on the struggle for power of the opponent and a foreign policy of restraint. Finally, the article proposes three angles to contain the Islamic State. Each angle exploits the persisting characteristics of the Islamic State as a revolutionary actor with internal contradictions and promulgating specific narratives which containment can engage.

Facing ISIS's transformation, advocates of containment argue that such policies can halt the opponent's territorial advancement, and bolster regional and communal resilience, but not ideology (Jordan & Rubin, 2016;Zakheim, 2014). The problem, then, is that containment seems inapt to counter ISIS, as it no longer has a territorial stronghold. Containment strategies are thus seen as successful when confronting a homogenous hierarchical structured entity controlling territory (which ISIS used to be) yet failing when confronted by a network (which ISIS developed into). This article instead asks why containing ISIS was successful in the first place and why an actor that lost its territory but keeps spreading its ideology and violence can still be contained. Rather than convulsively examining containment's transferability, the article argues that there are further means of containing ISIS if containment addresses ISIS's hybrid nature.
The article makes two contributions to contemporary security studies. First, it points out why containment was successful to curb ISIS. Existing proposals of containment (e.g., Jordan & Rubin, 2016;Juneau, 2015;Staniland, 2017;Zakheim, 2014) rarely explicate why ISIS could be contained in the first place. However, an evaluation of containment is more than reconstructing a past strategy. Therefore, second, the article points out why a transformed ISIS can still be contained. Today, ISIS might lack the traditional "containable" attributes, such as a territory, but it remains hierarchically structured as an insurgency and terrorist movement. The focus on the (American and Iraqi led) anti-ISIS coalition illustrates why there is more of a continuum of means of containment against ISIS rather than a clean break between past, current, and future attempts of containment. ISIS remains a hybrid actor, combining secular and religious forms of structure and agency, which make it containable.
The first section of the article distinguishes containment against states and non-state actors. Doing so advances understandings of the historical roots of containment as well as options and limits of the concept's transferability. The second section conceptualizes ISIS's nature in terms of its secular and religious appearances. The third section sketches out three angles of containing ISIS that have been successful and, if adapted, might be successful again. Each angle exploits the persisting characteristics of ISIS as a revolutionary actor with internal contradictions, promulgating specific narratives. Those characteristics can still be contained, if only to varying degrees. International efforts to contain ISIS can be informed by historical experience but containment needs to adapt to new circumstances of the transformation of the subject rather than simply copying the principles of past strategies. The conclusion stresses that further means of containment should involve a restrained foreign policy.
From containing secular states to containing religious non-state terrorists George Kennan's "Mr. X" article "The Sources of Soviet Conduct," originally a cable from Moscow to Washington in 1946, first proposed a foreign policy of containing the Soviet Union. For Kennan (1987b, p. 868), containment was the American policy to "increase enormously the strains under which the Soviet policy must operate … and in this way to promote tendencies which just eventually find their outlet in either the break up or the gradual mellowing of Soviet power." Containment aimed "at curtailing the USSR's ability to gain influence via psychological and political means, particularly among its immediate neighbours" (Aran, 2012, p. 837). The Soviet leadership was inherently dependent on an external threat to stimulate internal political legitimation. Hence, Kennan and others concluded that the domestic ideology of the Soviet Union was not a determinant of its policy but served its legitimation for political conduct (Gaddis, 1977(Gaddis, , p. 874, 1981Kennan, 1987a, p. 886). 2 During the Cold War, a consensus among Western, particularly American foreign policy makers prevailed over the aspects of containment policy (see the "state" column on Table 1). Gaddis (2005, pp. 381-385) summarizes containment's aspects as follows: First, containment's main subjects were states whose character was clearly identifiable. Most prominently, the containment of the Soviet Union estimated Soviet power as a clearly identifiable (territorial and ideational) monolithic block (e.g., Kennan, 1968Kennan, , pp. 369-370, 1982. The state based strategy of containment, then, "depended not only on the fear of all-out war, but also upon the existence of identifiable regimes that could manage the running of risks short of war" (Gaddis, 2005, p. 382).
Second, the reliance on containment required that "the adversary to be contained share one's own sense of risk" (Gaddis, 2005, p. 381) (i.e., of a Third World War). This aspect persisted throughout the Cold War and among ideological currents in East and West. Containment, in other words, "presumed threats [emphasis added] from states seeking to survive" (Gaddis, 2005, p. 384). Eventually, containment succeeded against those regimes because they had no set timetable. "Convinced that history was on their side, Stalin and his successors were prepared to be patient: that bought the time needed for containment to demonstrate that they were wrong" (Gaddis, 2005, p. 382). Third, containment was possible because of an almost uncontested American hegemony that limited the world political context in terms of ideological alternatives. For "as long as the Soviet Union was the alternative, there was always something worse, in the eyes of most of the rest of the world, than the prospect of American domination" (Gaddis, 2005, p. 384). Containment remained contested but endured the Cold War and policy planners and strategists have been inclined to look for containment's transferability to the post-Cold War context (Shambaugh, 1996;Wilson, 2007). However, when using the concept of Cold War containment, policy makers and scholars alike have often ignored the changed political contexts (Smith, 2014) and the character of containment's subjects. In particular, the rise of hostile non-state actors made it harder to transfer original aspects of containment (see the "non-state" column on Table 1). Ideological contexts of nonstate actors range from state-based to non-state secular and religious terrorist actors.
Moreover, the threat posed by these actors is hardly clear or limited, ranging from locally to globally operating terrorist groups, making it difficult to compare the Cold War with the "war on terrorism" (Ahrari, 2007). Few studies therefore flesh out an approach of post-Cold War containment to counter non-state terrorist organizations (Gaddis, 2005, pp. 380-391;2011, pp. 249-275;Shapiro, 2007). At the same time, containment has successfully been used, for instance, against locally based terrorist actors (Aran, 2012; see also Rid, 2012). These successes indicate the transferability of containment's aspects if the subjects show leanings toward the limited aspects that Cold War containment relied on. Why the Islamic state could be contained What, then, about the conception of ISIS as a subject of containment? ISIS is neither a state, nor a mere non-state actor. Given ISIS's apocalyptical rhetoric and terrorist methods, it has a different perception of threat than an entity seeking to survive. ISIS arguably operates under an unlimited political context as it continues to attract followers from around the world. To pin down ISIS's character, Table 2 introduces a more detailed conceptualization of containment's subjects. This conceptualization illustrates the subject's different configurations of its substance ("structure") and justification for its mode of operation ("agency"). 3 Based on secular structure and agency, Type I are nation states, the original subjects of containment (e.g., the Soviet Union). Type II are secular non-state actors (e.g., terrorist actors). Type III are actors, which structure rest on a traditional state-based structure but partly operated and justified by religious agency (e.g., Iran). Type IV are non-state actors, operating and justified by a religious mode of agency (e.g., Al-Qaeda).
The cases of actors such as Hezbollah and Hamas illustrate that there are actors which structure and agency transcends the dichotomy between the different types. Yet ISIS, in particular, cannot be reduced to either one of the types. Rather, its hybrid nature moves among and transcends all four types. From the perspective of containment's aspects outlined above, containing ISIS worked as long as it showed the limited characteristics that made other states (i.e., Type I or III) and non-states (e.g., locally based terrorist actors, i.e., Type II) containable (Aran, 2012;Shapiro, 2007, p. 77;Trager & Zagorcheva, 2005. In the case of ISIS, the assumptions of containment's subject also point out certain clear and limited substantial (i.e., structure) and functional (i.e., agency) manifestations (Fromson & Simon, 2015;Kaplan & Costa, 2014, pp. 953-955).
The actions taken against ISIS rely on a limited approach, focusing on military operations to recapture territory and prevent ISIS's territorial expansion (Jordan & Rubin, 2016;Juneau, 2015;Posen, 2015;Walt, 2015aWalt, , 2015bZakheim, 2014). These actions made sense as long as ISIS showed the limited characteristics that made other states and non-state adversaries containable. Other than halting the territorial expansion and decapitation strikes (e.g., attacking ISIS's Type I outlets), the main inclination of past and current approaches, the long-term goals, and the strategy to achieve them remain vague. In other words, the actions taken so far focused on single parts of ISIS's nature that, in fact, overlaps the boundaries of the four types in Table 2. To comprehend ISIS's nature and continue its containment, a better grasp of its hybrid nature is thus necessary.
The power of ISIS originally depended on its seized territory and center of gravity, providing it with a competitive advantage over its rivals (Byman, 2016, p. 131;Pollard, Poplack, & Casey, 2015). Other than Al-Qaeda, for example, "ISIS, for all its barbarity, is both more pragmatic and more utopian. Hand in hand with its tremendous capacity for destruction, it also seeks to build" (Callimachi, 2018;Gerges, 2017;Stern & Berger, 2015, p. 73), based on a "masterplan" (Fishman, 2017). ISIS, either during its high watermark or now, is not only a terrorist group that can be dealt with tools from the counterterrorism box alone. To equate ISIS with terrorism is misleading (Byman, 2016, p. 129;Cronin, 2015;Kilcullen, 2016). Rather, because of ISIS's pragmatic and conventional tenets, it was predestined for a political handling and counter measurements such as containment.
There is a striking resemblance of the Cold War outline of containment and the containment of ISIS. For Kennan (1987b), the political personality of Soviet power as we know it today is the product of ideology and circumstances: ideology inherited by the present Soviet leaders from the movement in which they had their political origin, and circumstances of the power which they now have exercised for nearly three decades in Russia. (p. 852) ISIS's power is the product of the ideology of Islamism and of circumstances, such as civil war, the Sunni-Shia rivalry, and the consequences of military interventions (Malkasian, 2017). Not least is ISIS the product of its leaders' ideology, inherited from movements such as al-Qaeda in Iraq and the Baath party in which they originated (Bunzel, 2015;Cockburn, 2015;Kaplan & Costa, 2014;McCants, 2015aMcCants, , 2016Natali, 2015;Steward, 2015; see critically Whiteside, 2017). Some argue that ISIS is a cult (Gaub, 2016), making it cohesive and agile (Barbato, Hantscher, & Lederer, 2016). In any case, the discussion of whether ISIS is also a religious actor with devout agents matters (Cottee, 2016;Dawson & Amarasingam, 2016;Emon, 2015). The "religious" mode of ISIS's agency is an essential part of its conception. Its theological rhetoric, then, must be interpreted in particular contexts such as the circumstances and configurations of power (see also Grzymala-Busse, 2016;Lynch, 2014, p. 91).
Such a view on ISIS's "religious" agency challenges the mainstream wisdom and promised success of supporting moderate clerics and religious freedom to counter ISIS (McCants, 2015b). Rather, states like Saudi Arabia that hold onto a similar brand of Islam (McCants, 2016, p. 136) are prone to play an important part in containing ISIS. This is not least because people are "longing for something in their history, in their traditions, with their heroes and their morals, and the Islamic State, however brutal and repugnant to us and even to most in the Arab-Muslim world, is speaking directly to that" (Atran, 2015). Liberal, Western counter-narratives are an insufficient response, partly because they do not exist as the next section illustrates.
ISIS's overlapping modes of secular and religious agency and state and non-state structure (see Table 2) suggest, "a severe religious theology is not incompatible with practical considerations" (McCants, 2016, p. 155). ISIS's political and religious conduct is a matter of interpretation and configurations of power. Introducing a strict separation of secular ideology and political religion (i.e., vs. Types I/II and Types III/VI) is thus not much of a conceptual use (Agensky, 2017;Gunning & Jackson, 2011;Sheikh, 2012). This is obvious in the second angle of containment, delineated below. It argues that, in the long run, ISIS suffers from a contradictory internal strategy-making process (O'Loughlin, 2018): ISIS relies on a political religion (the establishment of the Caliphate), yet it builds on a strategic doctrine, promulgated for example by Abu Bakr Naji's (2006) The Management of Savagery, the blueprint for ISIS's seizing of power (McCants, 2016, pp. 79-84). All of this suggests that ISIS cannot conveniently be located in any of the four idealtypes of Table 2. Only attacking ISIS's outlets in either type ignores its hybrid nature.
ISIS, then, is not a "mystery" (Anonymous, 2015). It is a revolutionary movement that replaced existing state structures with different ones (Byman, 2016, pp. 144-145;Walt, 2015a, p. 43), yet it is also a brutal insurgent organization (Pischedda, 2015) motivated by a theo-political agenda. "New" is the global visibility of ISIS's violent spectacle. Its brutal violence mobilizes victims to enact the perpetrator's political superiority (Friis, 2015(Friis, , 2017). ISIS's violence works as its call for self-sacrifice in the cause for a devoted commitment to the Caliphate (McCants, 2016, pp. 148-151) illustrates. Using symbolic expressive violence to enact political superiority (Kahn, 2008) creates and sustains political meaning. Violence thus works as an instrument to coerce political and ideological opponents and as a motivator. Either way, ISIS's character discloses the human desire for the struggle for power, no matter if based on religious or secular narratives. In particular, ISIS's aspirations for ideological purity aim at salvation, carried by the expected apocalypse (McCants, 2016;Wood, 2015). 4 The expectation of sectarian war remains a prominent feature of ISIS's apocalyptic vision and a prominent feature of its foundational experience (Gerges, 2017). This vision exploits attempts of pointing out that intra-Islamic violence is useless. Rather, this kind of violence is an essential part of ISIS's apocalyptic narrative, illustrated below at the third angle of containment. However, characterizing ISIS merely as an actor that seeks apocalyptic confrontation ignores the historical contextualization of terrorist movements. Modern terrorism always has been a power struggle: "central power versus local power, big power versus small power, modern power versus traditional power. The key variable is a widespread perception of opportunity, combined with a shift in a particular political or ideological paradigm" (Cronin, 2002, p. 35). Military success against ISIS-controlled territory illustrates that, rather than holding its ground at any price, ISIS showed territorial flexibility. This is the case even when it comes to strongholds that are ideologically and theologically essential in ISIS's legitimation narrative. A case in point is the town Dabiq which was expected to be the site of an apocalyptical showdown but abandoned quickly when anti-ISIS forces approached (Winter, 2018;Kadercan, 2017).
ISIS resembled and challenged the basis and organizational principles of western political order build on the sovereign territorial state (Barbato et al., 2016;Nuruzzaman, 2015). Assuming enemies as monolithic political entities remains a vitriolic feature of Western strategic thought (Kelly, 2008, p. 12). The same applies to the U.S. strategy of countering transnational terrorism, dealt with as a would-be state, which inevitably outdate containment that relies on certain clear aspects. However, a failure to contain terrorist organizations does not mean that it is a failure of containment (Shapiro, 2007, p. 77), let alone that ISIS is not merely a terrorist organization. ISIS is a hybrid actor, at the same time an insurgency movement, would-be state, and a social movement that needs to be contained accordingly.
The realist case for containing ISIS So far, this article has argued that there are good arguments for the original aspects of containment to be applied toward ISIS. When focusing on ISIS's temporal specifics, these aspects were successful because they confronted not a completely novel actor. Future containment can only be successful if it addresses ISIS's hybrid nature located in the non-static center of Table 2. This outline of ISIS's nature, illustrated above, moves beyond the diffuse dichotomies of state/non-state and secular/religious types of actors. For future containment, there is more merit in turning to containment's theoretical background ideas rather than focusing on the transferability of the policy's original aspects. Because containment emphasizes restraint in foreign policy conduct, the academic theory of Realism has been the blueprint of containment strategies. The struggle for power and the balance of power is a central tenet of Realism (Gottfried, 2010;Russell, 1999), 5 also revealing normative implications.
While emphasizing the primacy of diplomacy (Mayers, 1986;Shapiro, 2007, p. 35), containment sketched out a strategy to counter opponents beyond military means. Containment was never meant to be a strategic doctrine with regard to U.S. military involvement in the Korean War or fighting proxy battles in Africa, South America, or South East Asia (Kennan, 1968, p. 368;366). This is even more so today when containing ISIS. Kennan (1987a, p. 889) was aware of containment's shortcomings and contentions. Containment needs to start at home by restraining liberal interventionist impulses. Because restraint and patience do not promise a quick and cheap victory, containment is hard to sell facing ISIS's brutal atrocities that incite escalation. Nonetheless, containment's Realist background stressing restraint, diplomacy, a focus on power, and a modest approach towards military instruments offers a solid compass to present challenges (Angstrom, 2011;Larson, 1985;Porter, 2009, p. 305) without undue conceptual stretching.
The Realist background assumes that such a strategy alone cannot eliminate the threat. Containment needs to address the expansion of power, which is a prime maxim of ISIS. Ideological and religious justifications might be motivations for this struggle, but that does not change their outcomes. One of the major appeals of ISIS sustaining its legitimacy is its "ability to endure and expand." Yet those appeals are dependent on ISIS's ideological appeal which makes the ideological fight an actual one (McCants, 2016, p. 156). Hence, the transferability of containment is framed as a limited strategy and part of a broader effort to halt the expansion of ISIS but not to defeat or eliminate it (Dobbins & Jones, 2017, p. 60). Building on the Realist tradition, containment as proposed here, suggests an expanding scope of containment's measures, uttered by ISIS's hybrid nature. As the scope of containment encircling ISIS grows, the more containment moves away from transferable aspects (e.g., a clear and present danger represented by an identifiable subject). Containment, then, moves towards Realist principles that stress the engagement of the subject's struggle for power and a policy of restraint on the side of the container. Kennan's (1987b, p. 868) lines are still predictive: "no mystical, messianic movementand particularly not that of the Kremlincan face frustration indefinitely without eventually adjusting itself in one way or another to the logic of that state of affairs." This discloses the conceptual core of containment: The assumption that an opponent cannot endure endless frustration without eventually changing its conduct. The previous section illustrated that this frustration was partially caused by the success of containing ISIS over its failed territorial expansion (i.e., attacking its Type I outlet) and inhouse divisions between sectarian ideology and instrumental strategy.
The following tackles the question of how to deploy containment towards an actor that lost its territory but keeps spreading its ideology. Containing ISIS needs to engage a wide array of actors and institutions that Cold War containment did not need to bother much about since it was chiefly steered by the U.S. Containment against ISIS requires an international engagement of actors and institutions and a look beyond the national interests of states, other than those within ISIS's geographical sphere of influence. Other than during the Cold War, the world today provides more insights into the selfrepresentations and self-justifications of entities like ISIS. Today, it is possible to access the intentions of the adversary on many societal levels and make use of them in a counter strategy. Rather than doing "something," as the Realist tradition cautions (e.g., Lieven, 2006), today's situation also entails that containment at times needs to practice restraint rather than intervention. Finally, containment requires taking serious the fabric of societies and their social and religious factions that are rarely as clear-cut as the dichotomy between the different Types on Tables 1 and 2 suggests. Containment is able to cope with political actors' enduring struggle for power, regardless if they display material attributes that made them containable in the past or not. ISIS's characteristics and outlets struggle for infinite power, no matter if it is the attempt to run a state (Callimachi, 2018) or its religious aspirations and justifications for a Caliphate. Bearing within the "seeds of its own decay," like Kennan (1987b, p. 866) suggested for the Soviet Union, does not mean that those "seeds" lead to the organization's dissolution. Containment remains necessary because, despite its degeneration and transformation, ISIS remains lethal and will not vanish anytime soon.
Reactive containment calibrates the actor's actions with the actions of the opponent, for example seeking a balance of power, which makes it even harder for policy elites to argue for containment. Today, it is more likely that containment needs to be proactive and asymmetric (Shapiro, 2007, p. 48) 6 which is illustrated throughout the three angles of containment below. In order to successfully contain and not only to deter ISIS, those approaches must be proactive in the sense that they are not only immediate responses or reactions but also acts of their own choosing, even if that means restraint rather than intervention. Further means of containment relying on the strategy's Realist heritage can contain the current ISIS and help to prevent it from rising again to its infamous form. Building on ISIS's hybrid nature, the next sections also scatter worries over the efficiency of containment while indicating its limitations. In particular, the following exploits ISIS's by now lost territorial base that characterized it as a revolutionary actor; its contradictions; information strategy; and propagated narratives.

Containing a transformed "Islamic State"
This section builds on the outline of ISIS's hybrid nature and previous containment to illustrate why containment can counter ISIS other than stop its territorial expansion in the past. This does not rule out military means, which may well be needed (Kaplan & Costa, 2014, p. 953) and, eventually, rolled back ISIS. Yet history shows that military means are insufficient for effectively blocking the expansion of an actor's influence beyond its territorial expansion. Any kind of containment, past and present, encapsulates two inclinations that reflect its Realist heritage. First, the humanitarian and publicity induced necessity to act, deriving from the dilemma fabricated by calls for action without resorting to full-scale war. Those calls are the results of the brutal atrocities committed by ISIS that legitimized an intervention (Euben, 2017;Friis, 2015, p. 727). Second, the adaptive nature and ideological appeal of ISIS make its complete defeat unlikely. Military success should thus not be overestimated. Rather, containment might as well be a measure in a calibrated set of policies to confront a transformed ISIS.

Character
If ISIS is a revolutionary actor claiming to be a state, legitimized by Islamist ideology, then fortifying international society can contain it. This has been demonstrated by previous containment that attacked ISIS's reliance on a conventional center of gravity and power. However, the degeneration of ISIS's territorial strongholds makes this angle of containment more than an exercise in historical reconstruction. Jihadi proto-states have been a constant feature of Jihadism, which indicates that the state-like aspirations of ISIS are all but gone. Jihadi proto-states remain radical and uncompromising as to the pragmatic features because they seek the support of global hardliners (Lia, 2015, p. 38). In the case of ISIS, the pragmatic features proved to be enduring and have thus been an angle of containment in the past and perhaps again in the future if ISIS regains territorial strongholds. This angle frames ISIS as a revolutionary actor, which takes stock of a traditional territorial center of gravity and power (Byman, 2016;Cronin, 2015;Walt, 2015a) and not only as a transnational terrorist organization and social movement. Containment, in this case, means trusting that in the long run ISIS finds it "harder to rule than it is to conquer" (Phillips, 2014, p. 497;Pollard et al., 2015, p. 15), despite its post-Westphalian and post-Sykes-Picot rhetoric .
The case of Taliban diplomacy in Afghanistan before the United States toppled them, illustrates that regimes similar to ISIS (Jihadist ideology and hybrid structures) tune in with international society conduct as they reached out to the institution of diplomacy (Sharp, 2003). This is not to advocate for building an international society, which hems in and eventually integrates ISIS, thereby incentivizing normal political conduct and legitimizing ISIS as another government. Speaking of ISIS as an actor, an Islamic state, must not be conflated with the assumption of it as a homogenous entity. ISIS, as outlined above, consists of various ideological and societal branches (Gerges, 2017;McCants, 2016). ISIS is not exclusively a hierarchical entity like a traditional state. Nevertheless, its outlets continue to share the desire for power and the claim of ideological purity. No matter if ISIS vanishes in its infamous form or not, it "shows how even an actor that is, in theory, opposed to the institutions and practices of international society, inevitably had to engage with its discursive and material practices in order to establish its relevance" (Toros & Dionigi, 2017, p. 160).
To sum up, ISIS's claims of and actual statehood have been a successful angle to contain it. ISIS propagating of ideological purity to maintain the proclaimed Caliphate permits the anticipation that, "because territorial authority is a requirement: take away its command of territory, and all those oaths of allegiance are no longer binding." While failing to expand, ISIS "resembles less the conquering state of the Prophet Muhammad than yet another Middle Eastern government failing to bring prosperity to its people" (Wood, 2015). Therefore, ISIS is always at risk to lose its legitimacy (McCants, 2016, p. 156). This angle of containment, then, needs to take stock of institutions such as international law and multilateral diplomacy on which Cold War containment had little to say. Facing the transformation of ISIS, containment requires a global approach, calling for more actors than only those affected by its territorial expansion. Moreover, as the next section illustrates, containment needs to engage the legitimizing scripts for jihadist violence.

Contradictions
Recent efforts against ISIS relied on a specific window of opportunity. With the loss of ISIS's territory, this angle of containment might be increasingly moot. Nonetheless, this angle is not only interesting in hindsight of past containment successes. Rather, it illustrates the value of containment if ISIS or a similar entity gain a territorial foothold in the future. What is more, this angle points to the necessity of exploiting ISIS's legitimacy narrative, which likely continues to be based on trying to regain territory. Seeking a traditional territorial center of power, ISIS is in constant internal threat of being torn apart between pragmatists and the global base of hardliners whose support ISIS seeks to secure. The following angle of containment exploits those enduring internal contradictions of ISIS.
If ISIS's short-term success rests on combining opposites (i.e., religious fanaticism and strategic power seeking calculation), then it suffers in the long run from its internal contradictory strategy-making process. ISIS's military success rests on its ability to combine the opposites of theo-political and strategic calculation. ISIS lends itself to a rigid ideological legitimacy that attracts devoted followers. This is evident in the bulk of its media messages emphasizing the near apocalypse (McCants, 2016, Chapter 5;Winter, 2015). However, as recovered ISIS files reveal, it is also its ability to attract and integrate former members of the Iraqi Baath party and officers, making use of tactic and strategic military knowledge and intelligence to run a security state (Sly, 2015). This is not to say that Islamist rigidity and strategic military calculation do not seek the same power as other political actors. Politics, conducted by ISIS, is a struggle for power all along. While administrating and governing everyday political and bureaucratic life, ISIS seeks to expand its power (Al-Tamimi, 2015). This is obvious in Naji's (2006) "The Management of Savagery" and other material, promulgated for instance by Abu Musab al Suri or Anwar al-Awlaki or the propaganda strategy distributed in the journal Dabiq (Byman, 2016, note 33;Colas, 2016;Gartenstein-Ross, Barr, & Moreng, 2016;Reuter, 2015;Simons, 2016). 7 Over the long run, countering ISIS needs to engage this actor beyond "sacred values" and focus on Sunni Arab grievances and Iraqi nationalist beliefs embedded in this group. Targeting IS beyond its core believers also means understanding Baathist networks, structures and tactics; the role of territories and resources for Sunni Arab nationalist groups; the disputed territories issue between Kurds and Arabs; and effects of Iranian influences on Sunni Arab behavior. These issues will likely drive former Baathists and radical Sunni Arab nationalists in Iraq even after IS has been degraded, leaving the potential for IS successor groups to emerge. (Natali, 2015) ISIS's nature remains hybrid. It is composed of substantial Islamist ideology served by the "believers" and it rests on a strategy served by power-seeking individuals, likely ignorant of a religious purpose. The latter seek integration into political institutions to hold on to power. At that point the two natures, "Islamic" and "state," clash, making it even more prone for containment and, eventually, to roll back (Phillips, 2014, p. 498). The more the Caliphate becomes what it despises, the more intense internal rivalries will get. Containment, in other words, can also work "in the face of the decline of ISIS which is slowly worn down or collapses because of internal fragmentation" (Staniland, 2017, pp. 38-39). Nonetheless, it is important to recognize that ISIS did not fracture between its previous ebbs. ISIS's hierarchical resilience makes it even more important for containment to engage the actor's promulgated narrative.

Narratives
The communication strategy of ISIS is pre-eminent in countering it (Berger, 2015a;Berger & Morgan, 2015;Winter, 2017;Gartenstein-Ross et al., 2016;McCants & Watts, 2015;Stern & Berger, 2015;Weiss & Hassan, 2015). The well-orchestrated information policy of ISIS gives a three-folded rise to contain it. First, ISIS's open access "digital" and "virtual" caliphate attracts foreign fighters and sympathizers more than it seeks local support. Second, ISIS's use of brutal violence and illustration heightens the international awareness of its cruelty. Third, ISIS maintains a media system that attracts attention well beyond mainstream media coverage. Given the degeneration of ISIS, and thus the exhaustion of traditional options to contain it, this development opens new opportunities.
ISIS uses its communication strategy to shape the perceptions of followers and opponents alike, via narratives that set out to configure alternative perspectives (Atwan, 2015;Ingram, 2015, pp. 729-730;Pelletier, Lundmark, Gardner, Ligon, & Kilinc, 2016). Graphic displays are the more superficial part of ISIS's information strategy. Lengthy explications justify specific acts (e.g., beheadings). Those justifications aim to externalize the West and regional governments of their hypocrisies and shift the narrative to their own victimhood. Countering this information policy needs to empower indigenous media and police jihadists and their social media usage (Hegghammer, 2015;Ingram, 2015;Shapiro, 2007, pp. 102-108) and, eventually, disrupt this open source journalism (Sienkiewicz, 2018).
Merely participating in an ideological battle, however, buttresses ISIS's narrative for internal legitimation. The emerged practice of (particularly Western governmental officials) to call ISIS "Daesh" 8 can be criticized from this angle. The "recognition of the Islamic State by its name involves engagement with its political, economic and military as well as ideological force" (Siniver & Lucas, 2016, p. 64). Words matter and by calling ISIS by its self-declared name, this wording "is a precondition of mounting a challenge to 'legitimacy', confronting the claims of IS with the evidence of its often brutal behavior and policies, and its misreading of Islamic texts." Doing so illustrates that "'better ideas' cannot be imposed from the outside" (Siniver & Lucas, 2016, p. 79). Hence, calling ISIS "Islamic State" does not necessarily ascribe it qualities of an actor that it does not possess or if so, largely lost. If ISIS grounds its legitimacy on ideology and garners legitimacy in constructing counter-narratives and counter perceptions of the suppression of the Muslim world, then containment must engage its ideology, rather than directly countering it.
ISIS seeks to press its opponents into polarization and obedience (Byman, 2016, p. 150;Friis, 2017;Stern & Berger, 2015, p. 243). Pursuing a counter-narrative thus reinforces the polarization ISIS seeks. This is especially the case of attempts to sell a specific narrative of America and the Middle East. Such attempts face resistance as they are often mediated by an autocratic political order (Porter, 2009, p. 305). Analyses on how to counter ISIS's "war of ideas" (Tertrais, 2015) fail to notice that the strength of ISIS's ideological narrative only succeeds to mobilize a minority. As the majority is fleeing ISIS's territories, this forbids framing this conflict as one of ideas alone (Berger, 2015b). Although it shifts the focus to its status as a victim, the major trend of ISIS's public exploitation is to get rid of the "grayzone." The journal Dabiq approvingly quoted bin Laden: The world today is divided. Bush spoke the truth when he said, "Either you are with us or you are with the terrorists", with the actual "terrorist" being the Western Crusaders. Now, "the time had come for another event to … bring division to the world and destroy the Grayzone". (Atran, 2015) The challenge, then, is "to provide an alternative means of satisfying the quest for glory that motivates those who join in Isis's barbarism" (Atran, 2014) and the appeal of the illustration of this narrative (Cottee & Cunliffe, 2018), not to focus on constructing a counter-narrative which likely pours gas on the revolutionary flame of ISIS.
Whatever entity or movement ISIS eventually transforms into, containing it requires much more vigor of Western governments explaining why restraint is more promising than to give in to the desire for escalation. A strategy of containment also calls to engage and coalesce actors with a similar conceptualization and vision of religion who could influence the course of action of ISIS, other than (Western) military power alone can do. There is, then, no use in pursuing a strategic counter-ideological battle. This is especially relevant, given the potency of Islamist ideology is unleashed when suras and Hadiths are presented as mechanisms to understand broader contextual issues related to identity, crisis and solution constructs. Even the most jurisprudentially sound counter-IS case reinforces IS's central narrative if it is delivered or expedited by non-Muslim actors (i.e., the Other). Islamic proselytising by non-Muslims not only commands zero credibility, especially amongst those most susceptible to radicalisation, but also inadvertently undermines the "moderate" ideologues and community leaders who are so crucial in fighting extremism. (Ingram, 2015, p. 747)

Conclusion
The contradictions of ISIS resembled in its very name, made containment applicable and manageable. It claims to be "Islamic" and a "state," both parts struggling for infinite power. As Kennan (1987b, p. 866, 868) argued regarding the Soviet Union long ago, ISIS as well "bears within it the seeds of its own decay," for "no mystical, messianic movement can face frustration indefinitely." The weakness of ISIS, then, is its amalgamation of intolerance and ambition (Byman, 2016, p. 152). So far, containment took a grip and advantage of this weakness and ISIS's strongholds collapsed. Now the challenge is to deal with ISIS's ideological confidence (Cottee, 2016, p. 448) and transformation to a terrorist organization (Clarke, 2017) that eventually might seek to re-establish strongholds.
For those who stay, for those who sympathize with it, for those who are attracted to it, and for those who fight ISIS, the narrative accompanying the transformation and the heavy lift must come from within the region. The fight against ISIS already compromises a host of countries across the Middle East. The here presented angles of containment illustrate why such a course of action worked and might continue to work facing a transformed ISIS. However, the actions taken so far (e.g., military means attacking structural outlets or network nodes) remain ambiguous as to their long-term strategic goal other than to roll back ISIS from its territorial strongholds. The success of ISIS's early years set an example and formula for future jihadists. It would be a mistake to assume that starting with the presumption that any vision of "containment" is a wise policy. The U.S. and the West were rather effective in countering global Jihadism by employing disruption and interdiction. Yet those actions are missing a strategic outline and directorial political strategy of how further prevent actors such as ISIS from gaining influence, if not territory.
For all the theoretical engagement with Cold War containment is worth, restraint entails perhaps the most valuable insight. Policymakers are well advised to take Kennan's warning serious that containment needs to start at home as it "must not destroy what it was attempting to defend" (Gaddis, 2005, p. 389). ISIS's brutal acts incite global policy elites to actions and there are good arguments to address the publicly induced desire to act. In this regard, the analogy to Cold War containment is indeed a weak one. Those who want to contain and eventually roll back ISIS need to reflect on their own values. Misguided responses from its adversaries only fuel ISIS's propaganda potency and help to brand its failures as successes (Winter & Ingram, 2017). Certainly, it is hard to oppose the desire to act without a clear analysis of the present and immediate danger. There needs to be a political strategy of which containment may as well be a means but not an end in itself.

Notes
1. The following uses the term ISIS ("Islamic State in Iraq and Syria"). 2. The focus on Kennan is to set aside the influence of his peers who argued for a more robust version of containment (e.g., Thompson, 2009). 3. This conception does not use the structure-agency distinction (distinguishing Types I-VI) as a vehicle for positioning social theories' explanations. 4. The Wood (2015) piece provoked staunch criticism (e.g., Cottee, 2016). Here, its contribution is to point out another signpost in the framework of references illustrating ISIS's desire for orthodox purity (however "wrongly" interpreted). Critics claim that Wood falls to the common trope that ISIS is a product of Islam. This article does not engage in this discussion but rather points out an explanation of religion and violence of its own. 5. Kennan (1993, p. 11) did not consider himself a theorist. 6. The "flexible response" of the U.S. engagement in Vietnam might come close to asymmetric containment but its success is disputed (Gaddis, 2005, pp. 235-271). 7. For administrative documents of ISIS, see http://www.aymennjawad.org/2015/ 01/archive-of-islamic-state-administrative-documents and https://clarionpro ject.org/islamic-state-isis-isil-propaganda-magazine-dabiq-50/. 8. "Daesh" is the negatively connoted Arabic acronym for ISIS.

Notes on contributor
Jodok Troy is a postdoctoral researcher at the University of Innsbruck, Austria. Previously, he was a visiting scholar at The Europe Center at Stanford University (2016-2018; FWF J3906-G16), a research fellow at the Center for Peace and Security Studies at Georgetown University, an affiliate scholar of the Swedish National Defense College and a lecturer at the University of Applied Sciences Bfi in Vienna. His International Relations research focuses on religion, ethics, the English School, and classical Realism. He is the co-editor of a special issue of Contemporary Security Policy on "The transformation of targeted killing and international order." ORCID Jodok Troy http://orcid.org/0000-0002-9755-8144