Breaching the EU governance by decompression

ABSTRACT This paper introduces the concept of decompression as a specific process of differentiation. Decompression can be anchored as one of the phenomena of non-compliance, representing a distinctive phenomenon, however. Governments or leaders acting in a decompression way are not Eurosceptics and they do not want to reverse the course of integration. We define decompression as a sudden violation of an EU rule by a member state, which leads to immediate disruption of shared trust in a basic EU policy or principle. In the case of a crisis, we can see a ‘compression’, an unexpected crisis-driven demand placed on domestic institutions. Decompression is a relaxation of this pressure triggering the non-application of an EU policy or principle in reaction to changes external to the political equilibrium. It sheds new light on the persistent power of individual politicians to compromise European integration in an unintended way, so far under-reported by the literature.


Introduction
During the COVID-19 crisis, the EU experienced episodes of turbulence.Some controversies were triggered by external factors beyond the EU's direct control (the spread of the outbreak to Europe), while others were triggered directly by the responses of member states to the pandemic.Within days of the first cases of COVID-19 appearing in the EU, unilateral, uncoordinated action by some EU member states automatically made it difficult to find a common solution.The Czech Republic, Slovakia and some other countries, for example, completely closed their borders (which is against Schengen rules) and thus, with this unilateral step, avoided in advance any search for a unified border regime among the Schengen states.The argument for protecting the absolute security of their own populations outweighed any effort to find a multilateral solution.
The unilateral closure of borders was interesting in one respect in particular -it was not an essentially Eurosceptic step, since it was not taken by Eurosceptic governments, and it was not intended to send a signal to Brussels that the countries concerned were fundamentally dissatisfied with the functioning of the Schengen area or the free movement of people.Rather, it was a unilateral, one-off expression of concern about the spread of a pandemic, and perhaps also of concern that the EU itself would not be sufficiently effective in protecting Schengen's external borders.Although the move was not primarily Eurosceptic, it had potentially strong disintegrative effects.Some media even reported the end of Schengen, de facto one of the greatest projects of European integration.Other countries took the same path, and by the end of March 2020, a clear majority of EU member states had closed or controlled their borders (Peyrony, Rubio, and Viaggi 2021).Once this particular wave of the pandemic waned, step-by-step lifting of the measures followed, and the EU member countries returned to the previous regime and coordinated multilateral actions.
What does this example show us?It was not a process of classical disintegration, as the essential 'Eurosceptic dissatisfaction' was absent in a stricto sensu way (Vollaard 2014).Of course, many leaders criticised the EU, but not with the typical soft Eurosceptic argument that the EU does too much.On the contrary, the EU was criticised for doing too little, too late.
Similarly, it is clear that this was not a long-term, creeping and deliberate process aimed at weakening the quality of European integration.On the contrary, it was a sudden, unilateral and uncoordinated move.What was remarkable, however, was the impact of this action taken to deal with a sudden threat, which can be described as 'decompression'.Immediately after the unilateral steps were taken, there was a general feeling of uncertainty about the future of the successful Schengen project.The general fear and anger can be illustrated by the words of the French president Emmanuel Macron: 'The risk we are facing is the death of Schengen' (Rios et al. 2020).The process of 'decompression' described above was characterised by unilateral violations of applicable law by some member states, which did not inform the European Commission sufficiently about the border closures.
This conceptual paper introduces the concept of decompression as a specific mode of unilateral action, not being triggered for Eurosceptic reasons, that might lead to disintegration.It has, however, a specific, usually unintended and temporal disintegration effect that does not typically have long-term implications for the depth and quality of integration.We follow Szczerbiak and Taggart's (Szcerbiak and Taggart 2008, 3) concept of Euroscepticism and include both principal (hard Eurosceptic) and specific policy-issuesbased opposition against further expansion of the EU competencies (soft Euroscepticism).
The key point is that Euroscepticism is politically a clearly manifested position, not a decision made by coincidence, chance or default.Typically, once the compression is over, the member state returns to the status quo ante.
Building on the differentiation and disintegration literature, this article argues that there is a difference between decompression and 'mere' non-compliance.Decompression is not a softer version of disintegration, nor a synonym of differentiation by noncompliance, but a specific and distinctive phenomenon.Decompression differs from differentiation by non-compliance (Hofelich 2022a;Kreuder-Sonnen and White 2022;Scicluna 2021) in their motivations (purely domestic, non-Eurosceptic motivation, with no direct intention to deny an EU solution in the future when domestic compression relaxes in case of decompression versus conceived and directly EU-related motivation), b/ the political or legal framing (style of political action versus disagreement with a legal norm), and c/the timing of action (sudden versus deliberate/calculated).Decompression makes it possible better to understand and analyse such manifestations of non-compliance that do not primarily go against legal norms but disrupt established behaviour patterns.It sheds new light on the persistent power of political actors to compromise European integration in an unintended way, so far rather under-reported by the existing literature on differentiation.
We define decompression as a sudden violation or breach of an EU rule or rules by a member state, which leads to immediate disruption of the shared trust in a basic EU policy or principle.Under normal conditions, we observe compliance with the basic principles and following of the policy frameworks set or maintained by the EU institutions.Sudden change in the context or circumstances, a massive complication or challenge, such as a pandemic, creates pressure (Ferrara & Kriesi, 2022) or 'compression', an unexpected demand placed on domestic institutions and the domestic public that is so great that EU-related concerns are temporarily ignored by one state (or a small group of states) in favour of taking quick action to reduce the pressure.
We will first introduce the concept and its distinctive features theoretically.In the second part of the paper, we will briefly discuss examples of decompression.The examples -of the Covid, migration and financial crises -are presented in reverse order chronologically.

Exit, voice, loyalty and differentiation
The first days and weeks of the coronavirus crisis are aptly described by Rhinard (2020) as a 'blame game', when 'the fingers of government officials, pundits and commentators begin pointing in different directions.'After the initial shock in March 2020, the EU very quickly began to take measures leading to better coordination (Wolff and Ladi 2020).However, even these failed to close the 'holes' created after the initial decompression, when individual states took unilateral steps (unilateral border closures in violation of Schengen rules) that they were later unwilling to revoke.This example illustrates very well the specificity of decompression, which will be discussed further.
One reaction of the academic community might be to ascribe these unilateral acts to ongoing processes of differentiation, concepts discussed widely in the scholarly literature.The literature describing these processes (e.g.Jones 2018;Krastev 2012;Leuffen, Rittberger, and Schimmelfennig 2012;Rosamond 2016;Schmitter 2012;Vollaard 2014;Webber 2018) has made significant progress, especially in the last decade.
The decompression effect described above can be treated as one of the modes of differentiation.Differentiation is a very broad concept, encompassing a range of relatively dissimilar processes.Generally, the literature uses the term 'differentiation' (Leruth, Gänzle, and Trondal 2022) when discussing the 'other' path of a particular member state within European integration.Its various forms, whether the above-mentioned differentiated integration, differentiated disintegration or the decompression presented in this paper, have their origin within the interplay of loyalty, voice and exit, a conceptualisation (Hirschman 1970) key to the following argument.As Hirschman (1970, 79) puts it, 'As a result of loyalty, these potentially most influential customers and members will stay on longer than they would ordinarily, in the hope or, rather, reasoned expectation that improvement or reform can be achieved "from within".'As Stefano Bartolini (2005, 54) explains, the key question here is 'whether the EU is producing "loyalty" which I interpret to be those structures and processes of system maintenance represented by cultural integration, social sharing institutions and participation rights.Individual loyalty represents the psychological and emotional ties that mediate between exit and voice, increasing the cost of the former.'Thus, the low level of loyalty to the European integration framework demonstrated in this paper may serve as an explanation, a condition -although neither sufficient nor necessary -for why disintegration and decompression occur.Hypothetically speaking, weak loyalty is found not only among Eurosceptics, but also, for example, among those countries or politicians who have limited experience with European integration and have been socialised in the European Union for a relatively short period of time.What distinguishes disintegration from decompression is the nature of the exit option (Bartolini 2005;Vollaard 2014, 7).Exit is 'the' strategy of disintegration.In decompression, only a partial and, of special note, temporary exit occurs, and loyalty is not questioned politically, only 'tested' empirically and by chance, not by intention.
To summarise, the degree of loyalty is a trigger of differentiation, determining whether states choose the path of exit (disintegration) or voice (differentiated integration or decompression).

Differentiation, differentiated (dis)integration and decompression
The concept of differentiation is often treated somewhat vaguely, but an examination of key texts in the current debate suggests that it is a kind of umbrella concept (Leruth, Gänzle, and Trondal 2019;similarly;Gänzle and Wunderlich 2022) encompassing a diverse range of phenomena.In addition to the often-discussed, above-mentioned sub-concepts such as differentiated integration and differentiated disintegration, one can also look at the current debate and mention, for example, de-facto differentiation (Hofelich 2022a(Hofelich , 2022b)), differentiation by non-compliance (Hofelich 2022a;Kreuder-Sonnen and White 2022;Scicluna 2021) or temporary differentiation (Genschel and Jachtenfuchs 2018;Stubb 1996).The aim of this section is systematically to compare these concepts with decompression, which we argue is a unique phenomenon not yet conceptually well elaborated in the literature.
According to Schimmelfennig (2022, 619), whereas differentiated integration refers to a situation in which integration progresses overall but at least one state remains at the status quo or does not participate at the same level of integration as the others [. ..], differentiated disintegration is the selective reduction of a state's adherence to the integrated legal rules, which results in an overall lowering of the level and scope of integration.
In the case of differentiated integration, Winzen and Schimmelfennig (2016) refer to its 'negotiation', which at first glance implies the non-random and 'negotiated' nature of the phenomenon.The literature offers a similar picture in the case of the debate on disintegration or differentiated disintegration.There is an increasing effort to find a proper theory explaining disintegration, boosted in particular by Brexit (e.g.Martill 2021;Rosamond 2016).Rosamond sees disintegration as (1) a process, (2) existing over a long time horizon and (3) having effects that we cannot estimate.In any case, disintegration 'might transform significantly the EU institutional equilibrium, whilst simultaneously being constrained and shaped by it' (p.868).But how to classify situations that are sudden, temporary policies occurring impulsively, actions that do not tackle the EU institutional equilibrium in any extensive, substantial and durable way?Decompression is not automatically a first step leading to disintegration, but it can do so under certain circumstances.The starting points of decompression are different from those of disintegration.In order to understand the motivations of the state for taking action against the European Union (or individual Brussels institutions), it is as well to start with the literature describing the collective problem-solving dilemma.Jachtenfuchs and Kasack (2017, 601) write about states making 'choices between collective problem-solving and the protection of sub-unit autonomy on an issue-specific basis'.If necessary, according to the authors, exit (withdrawing from collective policies) and voice (influencing collective decisions) are offered to states as negotiating tools (Jachtenfuchs and Kasack 2017;Vollaard 2014).However, Jachtenfuchs and Kasack (2017, 610) add that in this context, 'the trade-offs sub-units make between these two conflicting objectives depend on their "cost-benefit calculation".'The expression 'cost-benefit calculation' conjures up the impression of a well-thought-out and rational strategic action by a realistic actor carefully considering the benefits and costs of a voice or exit option.This style of thinking then fits well with the discourse of disintegration, which is seen as a gradual process.But this approach has obvious gaps, in that it assumes strategy, it assumes calculation (see also Hirschman 1970), it assumes negotiation and it also assumes a strategic response by the EU actors (Bressanelli et al., 2020).However, it does not consider a more or less sudden crisis situation, and it does not consider negotiation lacking a real calculation being made by the actors involved.Genschel and Jachtenfuchs (2018) show that the Eurozone crisis and migration crisis enhanced dilemmas of integration touching upon the core powers of the state, therefore creating a situation different from the disputes over regulatory power and capacity within market integration.Besides the 'traditional' distributive conflicts, domestic politicisation might play a role.The relative winners and losers of integration can be expected to calculate their relative economic or political costs and benefits (Jones 2018, 445), making disintegration a medium-or long-term strategy, not a matter of hasty tactical choice.Frank Schimmelfennig (2018) offers a perspective of 'differentiated disintegration' in the form of opt-outs as a product of 'concerns about the preservation of national sovereignty in areas of core state powers in countries with strong, exclusive national identities' (p.1155).The narrative of sovereignty is typical also for many Eurosceptic politicians in Central and Eastern Europe (Hloušek and Kaniok 2020).Decompression, however, does not pertain to sovereignty discussions or issues.In response to the Covid pandemic, the Slovak and Czech governments closed their national borders in 2020, but there were no references to state sovereignty in their justifications or the media commentary.
Finally, yet importantly, Hans Vollaard (2014, 3-4) stresses another feature of disintegration, which is the multi-causality of the process.He explains how different economic and political causes contributed to the attempts at disintegration of the EMU during the economic crisis after 2008.Decompression as a reaction to a sudden change is a monocausal action, a swift reaction aimed typically at tackling one problem, not increasing its complexity.All this is quite logical: how could the initiators of decompression think comprehensively and take into account multiple reasons when decompression itself is a phenomenon not based on a strategy that does not pursue any long-term goal concerning European integration as such?

Decompression as differentiation by non-compliance
After clarification of the relationship between decompression and disintegration, we must explain the relationship between decompression and non-compliance.Looking back and deeper into the waters of non-permanent differentiations, Genschel and Jachtenfuchs (2018, 185-186; see also Stubb 1996) work with temporary differentiation, which occurred, for example, when Cyprus and Greece introduced capital controls, or when some countries introduced internal border controls to manage the refugee influx in 2015.Temporary differentiation means a temporary exit from the rules.As Genschel & Jachtenfuchs stress, this involves taking severe economic or political risks and is followed by reactions from other EU member states to prevent the breakdown of such basic pillars of integration as the EMU or Schengen.At first sight, decompression looks like temporary differentiation.However, it does not call other member states into action.The temporary introduction of capital controls does not violate EU rules (European Commission 2015) and, according to some media reports, Greece was indirectly encouraged to act as it did by Eurozone finance ministers (e.g.Radiožurnál 2015).Similarly, the short-term introduction of border controls was not contrary to the current Schengen rules (because there is, of course, a difference between temporary border controls and unilateral total border closures for an indefinite period).Both of these examples of pre-pandemic action were thus more or less 'standard' and 'communicated' steps.Although both temporary differentiation and decompression are limited in time, the aim of decompression is not to establish or deepen any differentiation, just to 'solve' a specific problem (whatever it may be).Moreover, decompression does not include elements of externalising crisis management (Genschel and Jachtenfuchs 2018, 190-191); on the contrary, it is an effort by a nation to manage a crisis on its own, with no attempt to coordinate with others.Leruth et al. (2019) offer similar examples while working with the concept of de-facto disintegration, using Sweden's non-participation in the EMU as an example.However, the Swedish case is not a result of acute pressures within a particular crisis; the persistence and predictability of the policy in no way threatens law and order, does not provoke shock and tension and does not jeopardise the internal functioning of the Union.
Within the context of existing concepts of differentiation, decompression can best be anchored as one of the phenomena of non-compliance (Hofelich 2022a;Kreuder-Sonnen and White 2022;Scicluna 2021).The current debate deals with the concept of noncompliance prominently in reference to legal norms.Scicluna (2021, 658) distinguishes three categories: 1/forestalling compliance through legal and/or procedural challenges to a legislative initiative, 2/avoiding compliance by exploiting loopholes in a legal regime (a 'lighter' form of wilful non-compliance) and 3/outright non-compliance (a 'stronger' form of wilful non-compliance).In a similar vein, Kreuder-Sonnen and White (2022, 961) write about 'transnational emergency politics' or 'governance by emergency' (White 2019) and discuss examples in which states' actions can be understood as 'the politics of necessity'.This 'unilateral exceptionalism' (Kreuder-Sonnen and White 2022, 958) historically stems from the fact that 'many international legal instruments, especially in trade and humanrights regimes, include exception clauses allowing states to derogate from treaty rules in cases of national emergency.Even without such formal authorisation, however, governments regularly assert their discretion when they see vital interests threatened.'The noncompliance literature cannot be denied a solid understanding of the motivations of states to deviate from EU rules.However, it can be criticised for being too general in its coverage of a wide range of non-compliance phenomena that need to be distinguished from activities and deeds that have primary motivation and logic in a purely domestic context but can reach beyond the realm of a member state into EU politics.In other words, the problem with this otherwise very useful term is that it mixes cases that differ, among other things, in the circumstances of their emergence, in the motives of non-compliance and in the general context explaining the circumstances of, and causes for, non-compliance under compression.
Decompression is not mere non-compliance with EU law.It is an action taken by a national politician who does not acknowledge the possibility of reaching a European solution and precedes it with (often chaotic) unilateral action.Decompression is not a deliberate delimitation of existing law, it is rash and short-sighted political behaviour.It differs from other non-compliance phenomena in its emphasis on politics (and not law).It allows for a better understanding of the problems in achieving the goals of European integration through such behaviour of actors, where they reject standard negotiation processes and decompress, indicating a preference for unilateral solutions over multilateral ones.

Decompression, its motives, context and definition
As detailed above, decompression is not just a metaphor, an allegorical term describing any process of partial disintegration or differentiation.It is a specific and peculiar phenomenon, typically occurring at a time of crisis, which is characterised by several features: decompression is unexpected, sudden, and often comes from unanticipated places and for unforeseen reasons.
We can employ the postfunctionalist argument on the politicisation of European integration in the sense of mobilising against the EU at the national level (Hooghe and Marks 2008).Ferrara andKriesi (2022, 1361) add that 'when the spatial distribution of crisis pressures is asymmetrical, we expect the crisis to catalyze an identity logic, which heightens the politicization of European integration and generates greater dissensus across EU member states around the process of crisis resolution.'According to Hutter and Kriesi (2019, 996), politicisation implies European integration becomes 'part and parcel of a new structuring conflict', which 'raises fundamental issues of rule and belonging and taps into various sources of conflicts about national identity, sovereignty and solidarity'.
Although the issues triggering decompression might touch upon the core powers of the state and identity-based policies, they do not aim to raise any fundamental political conflicts.Decompression does not assume any 'logical' politicisation of the EU; typically, it is treated rather as a technocratic decision to solve a problem and reduce pressure on society.Eurosceptic parties, the usual suspects of politicisation, do not cause decompression.A Eurosceptic party, of course, if it is a ruling party, does not typically cause decompression in the sense of shock and chaos since non-compliance is a 'natural' reaction here and there in the case of such parties.Conflict between the government and opposition, a second source of politicisation (Hutter andKriesi 2019, 1000), might go on, yet the polarisation is not durable, since decompression is a time-limited action.Actors triggering decompression do not question fundamental institutions or procedures, as they would when politicising the EU (Bressanelli, Koop, and Reh 2020, 330), they 'only' temporarily bypass them.Also, decompression provokes none of the depoliticisation reactions typical of unelected EU actors (Schimmelfennig 2020).From this perspective, decompression is actually an act of impulsive micromanagement, not a product of a systematic, well-thought-out strategy.(Table 1) What is the context, the cause of decompression?First, there must have been a compression, by which we mean a sudden external pressure, a change in normal conditions strong enough to place stress on the member state's political institutions, most typically challenging the government.Ferrara andKriesi (2022, 1356) define 'crisis pressure' at the EU level as 'both functional and political challenges originating from "real world" conditions which beseech policymakers' attention' and call for the analytical extension of this concept.We define compression as a specific version of crisis pressure driven primarily by domestic concerns.Compression primarily impacts the particular member state, affecting policy makers and citizens.Compression might have repercussions at the EU level, too, yet for national policy makers at the moment of compression, solving a domestic problem, calming the domestic public mood and decreasing the level of compression is more crucial than concerns about EU institutions and other member states, despite the potentially adverse reactions of EU institutions or the other states.
Compression driven by a sudden and harsh change in external conditions drastically increases the costs of loyalty, by which we mean compliance with the rules and regulations of the EU.As the migration (Scicluna 2021) or Covid events showed, some crises can catch policy makers unprepared, increasing the tension and the demand for a quick and creative solution, which may 'require' departing from long-term practices and rules.The sudden and dramatic character of the situation makes voice at the EU level an inefficient tactic, since the government is facing increasing domestic pressures.The way out from this situation might be decompression, a specific kind of temporary exit, an act made in haste without considering the wider context and consequences.
To be sure, an erosion of confidence in law and order might occur, i.e. the application of law and rules on EU territory whose enforceability is normally beyond all debate.The erosion of trust in fundamental principles might lead to a sudden change in pressure implying a state of uncertainty and chaos.Yet it is not a challenge to integration by intention, and after the conditions causing compression recede, the member state or political actor might return back to the status quo ante and obey the rules again.Simply put, decompression does not mean a permanent decrease in loyalty vis-a-vis the EU polity.
Figure 1 shows the typical process of decompression.Compliance with behavioural patterns expected by the EU and basic loyalty to the political system of the EU is the 'normal situation'.Sudden external change can cause compression and domestic stress and change the perception of the domestic political elite: loyalty seems to be less important than taming the angry or stressed local public, voice seems to be a tactic that takes too much time and temporal exit seems to be the politically accessible way forward to mitigate the issue and reduce the pressure.After the decrease in pressure via temporary non-compliance, the member state typically opts for loyalty again and returns to the status quo ante.
To conclude this section, the features of decompression can be precisely defined as follows: 1. Decompression is a reaction to compression (see Table 2), i.e. to a state of affairs resulting from a crisis that calls into question the EU rules and presumes coordinated actions/behaviour of member states; 2. Decompression is a preference for unilateral

Table 2. Compression and decompression: basic characteristics.
Compression Decompression The emergence of a crisis implying the need to find a quick solution.
A member state (or several states) looks for a unilateral solution without giving multilateral coordination or solutions a chance.A coordinated European solution seems to have priority in order to achieve maximum synergy and efficiency, yet it cannot be reached quickly and cannot fix the problem related to the increasing domestic 'call into the action'.
The state impulsively opts for its own solution within its territory.
EU institutions expect the EU member states to demonstrate a certain basic level of loyalty that implies respect for rules and principles of international negotiation.
The state's loyalty to the EU and its potential solutions in times of crisis unexpectedly drops so much that the state chooses, often without any indication of prior consultation, a unilateral solution.
action; it is a particular type of non-compliance that is sudden and driven by the need to find a quick solution; 3. Governments or leaders acting in a decompression way are not typically Eurosceptics; they do not want to reverse the course of integration, nor question the EU institutional equilibrium; 4. Decompression is usually of short duration, and the decline in pressure is followed by a return of the state to expected patterns of behaviour.Now that we have given a general delimitation of the concept, let us briefly discuss empirical examples of decompression.

Case study I: EU border closures during the first wave of the coronavirus epidemic
One textbook example of decompression is the situation in March 2020, when some (typically Eastern) EU countries closed their borders by unilateral decision.We will use Czechia and Slovakia as examples to demonstrate the point.In both countries, the compression was triggered by societal fears of the spreading Covid disease and the governments felt pressure to introduce any measures to prevent the spread of the infection.By closing the borders, more or less uncoordinated with other EU countries, they significantly disrupted the free movement of people within the Schengen area, but what is crucial here, with this unilateral step, they avoided in advance an effective search for a unified border regime among Schengen states.The move was problematic from a communication point of view -the policy was clearly not coordinated with EU institutions, nor with other individual member states and thus had significant consequences for EU citizens' views of the effectiveness of European institutions, as well as for the stability of the Schengen system.This follows from the almost immediate media reaction that introduced the narrative of the possible end of Schengen, as, for example, President Macron warned in March 2020 (Rios et al. 2020).Decompression brings with it an additional problem: the erosion of respect for law, systems and order.It is therefore not just the initial shock that occurs after decompression, as this can eventually be managed through crisis management.An unexpected challenge to Schengen was the informal Central European initiative to temporarily create a 'mini-Schengen', i.e. states that lift border controls between themselves.At the time, the Czech foreign minister Tomáš Petříček explicitly confirmed this initiative when he said, 'We think we could create a mini-Schengen allowing people to travel without border checks, tests or subsequent quarantine in mid-June'.The foreign minister was pro-European by nature, and his aim was certainly not to prepare for the end of a key project within the EU.The same applies for the actions and motives of the Slovak government at that time.
Petříček´s statement illustrates the specific nature of decompression -it was born in a crisis, created chaos, reduced trust in the rules and continued to do so with a certain persistence for several months afterwards (although the initial shock of closing the borders of several states in March 2020 had passed).This 'creative approach' to the functioning of Schengen worked as a trigger for the European Commission, whose vicepresident Margaritis Schinas immediately warned that the restrictions then in place should not be 'replaced by a kind of regional mini-Schengens that fragment our single market (. ..)This is not possible' (Koutsokosta and Dell'anna 2020).Genschel and Jachtenfuchs (2021, 352) characterised the decompression logic of border closures perfectly: 'security stands for the benefits of rebordering (. ..)Better poor and alive than rich and at risk.' In summary, all elements of decompression are evident in the case of border closures during the pandemic: 1.The Czech and Slovak governments responded to the compression in the form of social and political pressures and fears indicating that COVID-19 would be imported; 2. The governments' action came suddenly, unilaterally and without any attempt to discuss alternative solutions with other states; 3. Governments driven by no Eurosceptic motives did not demand a change in EU law or an exemption, but only dealt autonomously with a situation for which they did not give multilateral solutions a chance.The step soon provoked frustration among part of the European elite and concerns about the future of Schengen; 4. Overall, the decompression was only temporary and after a few months the situation calmed down, there was a return to the status quo ante and the issue of arbitrary border closures disappeared from the political debate.

Case study II: the procurement of sputnik vaccines
The use of a Russian vaccine against Covid in EU countries became a very controversial issue in 2021.The widely shared assumption that the use of vaccines in EU territory would be subject to the approval of the European Medicines Agency (EMA) was the subject of debate in several countries (Czechia, Hungary, Poland, Slovakia) about requiring only approval by the relevant national authority.For a long time, however, it was Hungary alone that disrupted the European 'system' by ordering and using Russian and Chinese vaccines.The decision by Viktor Orbán, Hungarian Prime Minister, cannot be described as a decompression, as it was more or less foreseen and did not cause any unexpected shock.
More significant in this respect was the move by Slovakia, where Prime Minister Igor Matovič unexpectedly ordered two million doses of Sputnik (Euronews 2021;Martuscelli and Gehrke 2021).
(1) Matovič was facing increasing domestic pressure, being heavily criticised for a lack of activity in purchasing vaccines.An increasing number of cases and the deteriorating capacity of the Slovak health system to manage the challenge reinforced the compression.
(2) Matovič demonstrates in this case that decompression can be provided even by an individual politician and his or her decision.He acted unilaterally not only vis-à-vis his EU partners but also without the pre-negotiated consent of his coalition partners (Guasti and Bílek 2022, 13).This move almost caused the downfall of the government coalition in Slovakia and was also noticed by the foreign media (Guasti and Bílek 2022, 13).
(3) Even though he did not react intentionally to cause problems at the EU level (Matovič is not perceived as a Eurosceptic), the critical reaction followed immediately.European media noted the fact that Matovič did not wait for Sputnik to be approved by the European Medicines Agency, which, according to commentators, could cause future problems in the recognition of such vaccinations for Slovaks travelling in Europe (Mortkowitz 2021).Moreover, there were media voices criticising the threat to the so far relatively unified European approach.As Ellyatt (2021) put it, the move by some Eastern European countries to endorse Russia's vaccine unilaterally is bound to raise the hackles in Brussels as it undermines the EU's wish for a unified approach, and a sense of equity over the distribution of vaccines.
The key to the whole story is that Matovič did not violate EU law with his unilateral action, because it allows a drug to be registered by a national authority.Politically, however, his action threatened the authority of the EMA, which was respected by the overwhelming majority of EU member states, and the so far unified approach of the member states.The fact that the case was not more widely discussed on a European scale was mainly due to the fiasco in Slovakia.It appeared that there was no interest from the public in the Russian vaccine and it was hardly used in practice.
As with the border closures, it is clear that this decompression policy was not motivated by Eurosceptic attitudes.The more or less pro-European Slovak prime minister merely took some steps too hastily to appreciate their impact at the time they were taken.However, his actions resonated significantly with foreign media, with concerns being raised about the impact of such a policy on the unified approach.
(4) In this case, we see also a relatively quick return to the status quo ante, when the non-loyal attitude of some EU countries towards the EU rules did not resonate more than for the next few months.Among other reasons, there was the decline of the pandemic and a shift of attention to the war in Ukraine.

Case study III: the German chancellor's reaction to the influx of migrants into Europe (2015) and FAZ (2022)
A classic example of decompression is Angela Merkel's summer press conference in 2015, at which she announced her readiness to accept large numbers of migrants, using the famous words 'we can do this'.The compression in this case stemmed from both (1) the fact that migrants were accumulating in peripheral EU states and claiming asylum in Germany, which in itself created pressure for a response (see also Auer 2022, 60), and (2) the sociological-institutionalist rationale or character of German post-war politics, in which the shared 'norm and belief' was the constitutional imperative that 'asylum knows no upper limits' (Mushaben 2017, 527).This was not, of course, an immediate, urgent pressure, but was nevertheless assessed by the Christian Democratic chancellor as a reason for a decisive response, i.e. a reason for decompression.In doing so, she de facto paralysed the application of EU law (the Dublin requirement), which obliged refugees to apply for asylum in the first EU country they entered (Mushaben 2017, 527).However, this case is far from being just a unilateral violation of EU law.The main argument underlying the decompression in this case is that this tense moment when tens and even hundreds of thousands of migrants were arriving in Europe favoured a unilateral step over the multilateral deliberation of European leaders that we would rather expect in the event of a Europe-wide crisis.The reaction to the chancellor's policy came early.The German opposition, as well as a number of European statesmen, criticised Merkel's unilateral decision.Although some studies later proved that the chancellor's remarks did not have a major effect on the size and nature of the overall migration wave (Faigle, Polke-Majewski, and Venohr 2016), many European (mainly Eurosceptic) politicians (for example, Babiš in Czechia, Orbán in Hungary or leaders of the AfD party in Germany) misused Merkel's move in support of their own political goals and overall Eurosceptical rhetoric (Auer 2022, 62-63).
The features of decompression in this case can be perceived as follows: Angela Merkel, by inviting migrants to Germany, (1) reacted to the compression in the form of thousands of migrants sleeping in the Hungarian main railway station, demanding to be transferred to Germany; (2) she took a sudden, unexpected unilateral step, which in the short term solved an acute problem perceived by German chancellor as a compression (although, in the long-term perspective, it might have problematised any common EU solution); (3) this step was nevertheless taken by a pro-European politician, who certainly did not want to correct the course of European integration; and (4) even in the case of the German chancellor's actions it can be observed that the initial shock of her unilateral move quickly turned into a search for a constructive and comprehensive solution to the migration crisis at the EU level.Merkel's step itself did not lead to long-term disintegration, but on the contrary to the intensification of the debate on deepening migration policy.

Case study IV: the Greek referendum in 2015
In the period 2010-2014, the position of the Greek government was limited to that of playing a passive role as receiver of rescue money under strict conditions and with austerity measures imposed by the Troika (EC, ECB and IMF), a situation that lasted until the victory of Syriza in the January 2015 election.In its 2012 campaign, Syriza attracted voters with a combination of pledges to waive the strict austerity measures but remain in the Eurozone.The same stance won the 2015 snap elections for Syriza and its leader Alexis Tsipras.His new government, however, faced a compression situation caused by a mixture of contradictions between his electoral pledges and efforts to play the antiausterity card and the fact that the original bailout wound down at the end of 2014 and the Troika imposed conditions for continued support.Another element of domestically driven compression was that the Greek parliament failed to elect a new president in December 2014, and therefore new parliamentary elections had to be called, increasing the political pressure on the Greek parties (Tsirbas 2018, 27).
Tsipras and his finance minister Yanis Varoufakis decided to bolster opposition to the austerity measures by calling a referendum in June 2015.The referendum can be seen as a typical example of an attempt at decompression.Tsipras wanted to get popular support for fighting the conditions imposed for the second bailout, which the referendum offered as 61% voted against the austerity measures.
This should not be classified as a Eurosceptic-motivated reaction since, in the longterm perspective, the positions of the dominant Greek political parties toward the EU remained blurry, with no elements of Euroscepticism (Sotiropoulos 2020, 61-63), and more than 80% of Greek citizens supported retaining the Euro (Sotiropoulos 2020, 75).Syriza's position in the 2015 campaign was, in general, pro-European (Tsirbas 2018, 32).In the end, however, Tsipras had to submit to the bailout conditions.Therefore, we can take this moment as an example of decompression that worked out only to some extent.The outlines of the long-term austerity measures demanded by the EU institutions remained untouched.Yet the domestic mood of compression relaxed, as Tsipras's victory in the second snap election in 2015 demonstrates.
We can see (1) a moment of compression here, given the unfavourable domestic political situation, in which the ruling party leaders decided to take (2) an extraordinary unilateral step by calling a referendum to mitigate the domestic compression and take the advantage in the upcoming elections.There was (3) no Eurosceptic motive in this decision and (4) Tsipras's government continued to cooperate with the Troika anyway despite the outcome of the referendum and because of the decompression of the domestic situation before the snap elections in 2015.In this case, we can clearly see the very temporary nature of decompression.

Conclusion: why does decompression matter?
Now that we have explained what decompression is and demonstrated how it works, we shall address the question: what is the added value of this specific concept?In our view, there are several reasons to continue the conceptual discussion on decompression, to identify further examples of it, and to consider the potential impact of decompression on European integration.There are five reasons for pursuing further research on decompression: (1) decompression can reinforce the 'crisification' of EU decision making (Kreuder-Sonnen and White 2022; Rhinard 2019), and, in general (2) the EU management of crises is weak and does not always compensate for the activities of the member states.Another analytical take-away from the decompression cases discussed above is that (3) not only outspoken Eurosceptics can contribute to setting EU integration at risk, and (4) even the most well-intended manoeuvres of pro-integration actors can sometimes contribute to disintegration.Finally, yet importantly, the conceptual debate on decompression can contribute to (5) theorising the role and displays of exit, voice and loyalty.
First, decompression might contribute to what Mark Rhinard (2019) calls the 'crisification of the European Union' and Kreuder-Sonnen and White (2022) 'emergency politics', a trend wherein the traditional methods of EU decision-making are replaced with crisis management and crisis and feelings of urgency are 'normalised' as the starting point for decision and policy making.Therefore, further research should investigate whether decompression, which is an example of emergency politics in the national context, can contribute to the expansion of the crisification of decision making at the EU level.Another avenue for the further research is to address the paradoxical situation that the decompression policies implemented at the beginning of the pandemic crisis are a genuine example of the crisification of EU policy making. 1  Cases of decompression can also be treated as another test of the quality and efficiency of EU crisis management.The case of border closures shows that, sometimes, EU institutions bound by EU legislation and its regulatory framework cannot react as quickly as needed to satisfy domestic demand for decompression.The closure of the borders during the pandemic crisis can be studied by EU policy analysts to find ways of reconciling the wish for quick action with the procedural and institutional limits of the EU.The case of Russian vaccine procurement is an example that raises the question whether EU crisis management is sound and credible enough to prevent the application of decompression policies by more EU member states.Both of these cases of decompression are of the utmost relevance for EU governance in periods of crisis.
Although we stress that decompression does not aim at disintegration, this might be a product of it, even if limited, differentiated and temporary.Any discussion of decompression cases should take place in the context of the disintegration literature as well as what is called 'enabling dissensus' (Ferrara and Kriesi 2022, 14-15).Since decompression typically occurs as an act triggered by a pro-integration actor, it can increase the risk of disintegration by enabling dissensus among member states and EU institutions that have the capacity to increase integration.The exact mechanisms of this are, however, yet to be explored and properly theorised.
Further, decompression contributes to the conceptual debate on non-compliance, its motives, sources and empirical demonstrations by stressing the political nature of certain reactions hampering the common solution or ignoring existing integration rules for non-Eurosceptic reasons, in a very limited period of time, and relaxing after the feeling of compression is over.More research on the termination of decompression, the return to the status quo ante and even the replacement of decompression with a new impulse for integration, as we saw in the pandemic crisis example, is worth consideration.
The study of decompression can contribute to discussions on exit, voice and loyalty.Hirschman (1970) ascribed these three strategies to citizens.We have seen that decompression involves a quick choice between exit and loyalty at the memberstate level or by national governments, respectively.European polycrisis (Zeitlin, Nicoli, and Laffan 2019) did not completely reverse what Weiler (1990, 22-23) calls 'closure of exit', yet the crisis decreased trust in common solutions and made exit less costly (Sydow 2019).Our decompression concept and cases show that a temporary and limited exit can be a quite attractive solution for governments that are afraid of mounting critical domestic voices.The theoretical debate on decompression as a specific form of exit challenging vulnerable loyalty can build on Bartolini's, (2005) use of the concept to stress the increasing importance of multilevel contexts for the exercise of different tactics of exit and loyalty.Decompression shows that domestic concerns may temporarily disable loyalty to the EU, making exit less costly because of ad hoc considerations covering primarily the polity and citizens of the member state.

Figure 1 .
Figure 1.An ideal-typical process of decompression.

Table 1 .
Differences between processes of disintegration and decompression.