A. Constitutional Imagination, Solidarity, and the Matter of Self-Critique

When Czech President Václav Havel returned in 2000 to speak before the European Parliament, he directed criticism to the adequacy of the European Union’s cosmopolitan and universalist aspirations. Havel’s concern was the immanent enlargement of the EU toward the East, which would soon include his own Czech Republic. The question of enlargement for Havel meant a confrontation with new horizons for the EU’s own self-understanding.Footnote ¹

He knew the incorporation of post-socialist states and their citizens, were they to be true equals in partnership, would require the European Union to confront much more forthrightly than it had before questions of identity, shared responsibility, and social justice across areas of very uneven economic development and distinct historical experience. In light of the 1999 NATO intervention in Kosovo and Serbia and the preceding turbulent acceptance in the mid-1990s of refugees from the former Yugoslavia, such questions would also prompt the European Union to consider its own commitments to the world—and to the world’s inherent and shifting plurality.

Recalling his previous address to the European Parliament in 1994, Havel drew parallels between the need to confront such questions and the dwindling legitimacy of Europe’s functionalist mode of technical and economic integration. If questions of value and identity became subjects for European integration only belatedly, it was because such matters seemed self-evidently clear after the horrors of the Second World War, Havel argued. And similarly, the meaning of “Europeanism” had become a question only belatedly because it, too, had deceptively come “so naturally.”Footnote ² But in the same way the EU’s functionalist constitution privileging a liberalized common market has in time proven inadequate,Footnote ³ so too have the seemingly “natural” perceptions of European self-understanding. “[I]f Europe has thought so little about its own identity in the past,” Havel said, “that is no doubt because it considered itself, wrongly, to be the entire world; or at least it considered itself to be better than the rest of the world, because it did not feel the need to define itself in relation to others.”Footnote ⁴

For Havel, there was a connection between finding an alternative to European functionalist law and recovering the meaning of one’s solidarity with others. The coming Eastern enlargement for Havel would require the European Union to think more carefully about how a deeper and new array of divergent histories, socioeconomic structures, and political expectations among states could be integrated in an overarching solidaristic commitment to continue living together. It would press the issue of which kinds of difference and diversity would be tolerated, which values and preferences would be accepted, and which would not.

But Havel’s concern was not merely to secure accommodation of Eastern and Central Europe in the already established legal space of the European Union. His vision of solidarity was more subtle and reflexive; it entailed a mutual encounter. In pointing to the naturalizing insularity of “Europeanism,” Havel connected the external dimensions of recognition among states with a process of internal critique within them. Solidarity here entails reaching out but also reaching in—reflection on one’s external obligations but also reflection on one’s internal presumptions of identity, authority, and self-understanding. To invoke Europe’s solidarity—following Havel’s line of thought—is inevitably an act of self-critical imagination. It is to call to mind other possibilities, other kinds of relationships with one’s own society and with others, and new responsibilities to the world.

One is reminded here of Giorgio Agamben’s submission that only when “the citizen has been able to recognize the refugee that he or she is—only in such a world is the political survival of humankind today thinkable.”Footnote ⁵ Agamben carries the figure of the refugee from its context in the laws of asylum to the heart of civic consciousness underpinning post-national law. In thinking through what is owed to the foreigner and the refugee, the citizen “clears the way” for new understandings of nationality itself—and its potential for realizing solidarity anew.Footnote ⁶

In this Article, I take inspiration from this idea—this connection we see, with Havel and Agamben, between post-national solidarity in Europe and critical imagination—and try to understand its consequences for European law and constitutional theory. Specifically, I aim to put forward a revised conception, in light of this philosophy, of solidarity as a legal principle.

Theorists of European integration of course have long conceived the post-national civic relationship to be a product of law. Solidarity beyond the borders of the nation-state was to be a practical realization of the “integration through law” project, a set of sentiments and commitments mediated by the form and force of legal agreement. Yet, in times of instability and crisis, European law has hardly secured such solidarity—for the social and economic freedoms of Greek citizens, for example, or the rights of refugees to safely seek asylum. These cases have seen, to the contrary, a punitive use of legalism to deny solidaristic politics. They are therefore paradoxical, poignant failures in need of explanation. Indeed, they suggest a serious limitation in the way European constitutional thought has imagined the constitutive links between solidarity and post-national law.

Solidarity as a legal principle has been given erratic and skeptical treatment in European jurisprudence, deemed an elusive and limited tool to pursue fair and mutual obligations among EU Member States and citizens. Indeed, scholars have observed that the concept has prompted complex responses from national politics, some concerned specifically that post-national solidarity carries considerable ideological residue of neoliberal market pressures as the valence of its solidaristic commitment. After more ambitious use in earlier case law, the European Court of Justice, for its part, has applied the principle reluctantly—and vaguely where it has done so. The ECJ’s hesitance to give solidarity clear legal effect reflects the degree to which its meaning remains both politically contested and philosophically inscrutable.

But this unsettled question of solidarity as a legal principle calls into question a key ambition of contemporary constitutional law: namely its role in social integration of a complex, pluralistic, and post-metaphysical polity. Because legality remains essential to the work of European integration in times of great diversity and instability, the relationship of solidarity to law in a post-national legal order merits greater scrutiny, perhaps revaluation.

This Article develops theoretical steps toward such a revaluation. On my account, post-national solidarity requires a certain kind of legal recognition that reflects (a) terms of mutual dependency and mutual responsibility, and, just as importantly, (b) a dynamic responsiveness to how such responsibility evolves outside of one’s control and thus requires critical re-interpretation over time. This latter responsiveness requires accepting a higher order of self-critique and challenging the subtle ways one’s desire for mastery continues to set the terms for recognizing others. And while this second dimension is therefore essential to changing the manner in which sovereign political authority is exercised, it has also been the aspect of solidarity neglected by theorists of post-national and European constitutionalism. This is a salient reason, I argue, why existing understandings of solidarity have proven insufficiently attuned to the claims of excluded or marginalized others—whether fellow Member States or individuals—and have instead often reproduced unjustified hierarchies and inequalities.

If, as Havel intimates, solidarity requires this responsiveness as a displacement of sovereign control, solidarity expresses not merely an enlarged conception of the common good. It also names a constitutional structure and a political culture in which citizens remain self-critical about the contours of that conception: its scope of enforcement, its normative meaning, and its grounds of legitimacy. Solidarity institutionalizes mutual critique as much as it does mutual support. This dynamic, reciprocal relation resists the passive ascription of nationality as a presumption that naturalizes membership and belonging for some over others. It asks citizens to understand the ways they are always in the process of seeking exodus and refuge in their own political lives—again, in Agamben’s phrase, to understand “the refugees they are.” Particular interpretations or applications of solidaristic commitments in law—whether in the internal market, economic governance, or migration policy—are predicated upon this broader imagined sense of how solidarity works.

This Article aims to illuminate this symbolic structure of solidarity and its concrete expression in EU law through a comparative analysis of contemporary constitutional theory and the evolving use of mutual recognition and mutual trust in the Area of Freedom, Security, and Justice (AFSJ), particularly in the context of European asylum law and ongoing reforms to the Dublin Regulation. The limitations of solidarity in this area of law specifically—where the citizen encounters the refugee and also encounters the idea of the citizen-as-refugee—suggest critical limitations to the European Union’s project of post-national constitutionalism, more generally. They pose profound questions, I believe, for how Europeans might better imagine solidarity to function through law and legal institutions—and as a principle to guide public life. Such reforms become all the more trenchant as the Treaty of Lisbon has given solidarity positive legal expression in Article 80 of the Treaty on the Functioning of the European Union (TFEU).

The Article is structured as follows: Section B elaborates the tensions of solidarity as a legal principle presently found in European law. To better conceive the relationship of solidarity to law, Section C turns to the most prominent expression of civic solidarity in contemporary European constitutional theory—the concept of “constitutional patriotism” articulated most comprehensively in Jürgen Habermas’s discourse theory of law. In elaborating the terms of constitutional patriotism, I trace how it finds clearest expression in the legal architecture of mutual recognition and the principle of mutual trust in EU asylum law.

Section D then develops a critique of constitutional patriotism’s limitations and illustrates how it also applies to the principle of mutual trust—with analyses of how EU law fails at once to protect individual rights and the equality of Member States. These limitations frame ongoing litigation over whether the principle of mutual trust must underwrite the forced transfers of asylum-seekers under the Dublin Regulation—notwithstanding the practice’s incompatibility with emerging standards of rights protection as interpreted by the European Court of Human Rights.

In light of this critique, Section E argues that solidarity as a legal principle is more compellingly conceived as a legal claim for mutual critique and responsiveness. Because responsiveness requires attention to the manifestations of particular harms, solidarity entails a form of judgment that centers the individual litigant and the particular case in an assessment of the adequacy of broader structural relations. This process is itself unpredictable and creative, driven by the exigencies of the case at hand. In the field of asylum law, I detail how the application of solidarity would offer a much-needed corrective to the structural imbalances of the Dublin Regulation. I conclude with reflections on the principle’s application in additional fields of EU law, as well.

B. Solidarity as an Elusive Concept in EU Law

Since Robert Schuman’s declaration that Europe shall be built through concrete achievements of “de facto solidarity,”Footnote ⁷ solidarity has been a central, if tenuous, feature in the European Union’s legal discourse. While the original European treaties left the legal meaning of Schuman’s words inchoate, the present constitutional texts establish solidarity among the EU’s “classical principle[s]” of law, which play a “normative founding function for the whole of the Union’s legal order.”Footnote ⁸ Article 2 of the Treaty on European Union (TEU) lists solidarity as a value “common to Member States,” and Article 3 TEU specifies that the EU shall promote solidarity between generations, among Member States, and among peoples.Footnote ⁹ Solidarity also reflects the principle of sincere cooperation found in Article 4(3) TEU which requires a collective commitment by both the European Union and Member States to fulfill their obligations “in full mutual respect” and correspondingly to prevent or restrain from conduct that might “jeopardize the attainment of the Union’s objectives.”Footnote ¹⁰ These provisions are intended to strengthen EU states’ commitment outlined in the TEU’s Preamble “to deepen the solidarity between their peoples while respecting their history, their culture and their traditions.”Footnote ¹¹ As Advocate General Bot has recently argued, solidarity reflects “the quintessence of what is both the raison d’etre and the objective of the European project” and in this sense forms an overarching “founding and existential value of the Union.”Footnote ¹²

Solidarity here aims to modulate and transform the national interest as refracted through responsibilities toward a European common good.Footnote ¹³ Von Bogdandy emphasizes that this evolving design of the treaty’s solidarity provisions affirms the EU as more than an intergovernmental agreement among States yet still distinct from a federal polity.Footnote ¹⁴ Nevertheless, the present and ongoing ways European law has asserted responsibilities of solidarity are difficult; their interactions are complex and often counterproductive in their attempt to redefine insular prerogatives of national sovereignty. Indeed, as it exerts specific pressures on the nature of national obligations, the meaning of solidarity remains controversial.

Beyond its status as a broad structuring principle of EU constitutional law, theorists have attempted to clarify how dimensions of post-national solidarity result from the normative and practical requirements of European freedoms of movement and the EU’s multi-level system of governance. Floris DeWitte, for example, has described the market, communitarian, and aspirational solidarities that oblige EU states to open certain kinds of social resources—such as unemployment insurance, welfare benefits, healthcare, primary and secondary education, et cetera—at various levels of governance to non-nationals depending on the nature and degree of their associational ties in the host state polity.Footnote ¹⁵ The intent is as much to establish non-discriminatory criteria for access as to preserve the general stability and coherence of national redistributive systems. Similarly, Rainer Bauböck has disaggregated T.H. Marshall’s original trichotomy of citizenshipFootnote ¹⁶ by space, time, and structure befitting the correspondingly disaggregated sovereignties above and below the nation in today’s complex post-national regimes.Footnote ¹⁷ Both theories rearrange solidaristic obligations by recasting relations of social belonging in terms of duration in time and proximity in space.

While there is much to recommend about these visions of differentiated commitments, there remain salient gaps in this manner of resolving the issue of post-national solidarity. Neither Bauböck nor DeWitte sufficiently addresses how these disparate levels of solidarity are meant to relate to one another—not whether they are compatible at any point in time, but more importantly how they mutually affect one another over the course of time. In this regard, Alexander Somek is less sanguine. He has warned that such a model acts upon national solidarity, “altering its meaning.”Footnote ¹⁸ Drawing on Tocqueville, Somek laments this distortion as an overriding ideological pressure of “individualism”: “the political worldview of neoliberalism” that reduces questions of public provision to financial viability, efficiency, and flexibility.Footnote ¹⁹ “Intriguingly,” Somek writes, “with the prevalence of individualism, national solidarity begins to appear both ugly and unkind,” no longer a marker of social commitment or public right but of potential private gain.Footnote ²⁰

Somek’s caution about the underlying neoliberal individualism in these arrangements of post-national solidarity seems all too astute in light of prominent failures of solidaristic action in Europe’s contemporary crises. Two examples—each, in a sense, with its epicenter in Greece—are symptomatic. Consider how the proposal by the European Commission to reform the Dublin Regulation concerning responsibilities to lawfully examine asylum claims serves, in fact, merely to retrench the system’s fundamental inequality toward peripheral EU states and to penalize asylum seekers in the interests of preventing their secondary movement.Footnote ²¹ And similarly consider—at the height of the Eurozone crisis—the legalistic invocation by Member States of the “no bailout” clause in Article 125 TFEU as grounds to refuse the needed restructuring of Greek sovereign debt and thus to affirm the morality play of “‘lazy Greeks” failing to repay hard-working “northerners.”Footnote ²² This forgets, of course, not only the structural factors driving the crisis, including the risk eagerly assumed by the northern banking sector financing southern loans,Footnote ²³ but much more importantly the significant leniency historically afforded under EMU budgetary rules to larger, more powerful states at Europe’s core.Footnote ²⁴

These shortcomings suggest the degree to which the use of solidarity in EU law remains in essential ways subordinate to existing, predominant interests—whether national or supranational and systemic—and its rarity and weakness in defending a transformative conception of the common good.Footnote ²⁵ Indeed, the Court of Justice of the EU, after earlier case law that pressed the boundaries of national solidarity’s scope in precisely the ways Somek found questionable, has been chronically unwilling to develop a general understanding of solidarity as a discrete ground for European obligations.

Following national backlash against the Court’s overly ambitious expansion of transnational social solidarity rights in the field of European citizenship law, the CJEU settled on a moderate position that accepted significant national restrictions to the provision of social assistance to those EU citizens who were economically inactive.Footnote ²⁶ Furthermore, in a number of recent cases concerning responses to the Eurozone crisis, the Court has declined to interpret the meaning or scope of solidarity as a legal principle. In Pringle, for example, the Court neglected to consider solidarity as a rationale to justify its narrow reading of the no-bailout clause—as Advocate General Kokott had urged—and instead upheld the legality of the European Stability Mechanism on the basis of its role in promoting sound budgetary policy among Member States.Footnote ²⁷ Similarly, the Court preferred a highly technical line of reasoning to assess compatibility of the ECB’s Outright Monetary Transactions (OMT) Programme with Article 123 TFEU without invoking solidarity as a guiding principle.Footnote ²⁸ And in the field of asylum law, even since the codification of solidarity in Article 80 TFEU in the Treaty of Lisbon, the Court has chosen to avoid relying on the principle in disposing of cases concerning the equity of the Dublin Regulation. In Halaf, for example, the Court sidestepped the explicit question whether the Dublin II Regulation’s “sovereignty clause” in Article 3(2) should be interpreted in light of Article 80 TFEU and resolved the case without mention of solidarity.Footnote ²⁹ Even where the Court has accepted that the Dublin Regulation must be read “in the light of” Article 80 TFEU—as it stated in the recent case affirming the binding nature of the emergency relocation scheme unveiled in 2015—its legal reasoning has left the content and scope of solidarity as a principle undefined.Footnote ³⁰ And in NS and ME, a case I will discuss in greater detail below, the Court accepted limits on the mandatory transfers of asylum-seekers under the Dublin Regulation while referencing solidarity merely in passing.Footnote ³¹

Some of the troubles here arise, no doubt, from difficult conceptual tensions among Enlightenment and counter-Enlightenment views on the relevant terms and bounds of solidarity.Footnote ³² But salient to the question of legal solidarity is another dimension of these crises: The disciplinary, often punitive use of legality itself. These responses disappoint, in part, because they employ the law foremost as a system of social management, absent positive reflection on the common good and judgments about what it might demand. Legal intervention is here conceived as reactive and constraining: a means to compensate for systemic deficiency, but without accompanying normative resources to critically examine the background presumptions on which present sovereign interests rest. As with Somek’s individualism, European law’s underlying metric of judgment for solidarity remains tied not to a polity’s normative commitments and sensitivity to the needs around them, but to an individual’s capacity to choose and to the legal system’s capacity to efficiently manage that choice. This signals an ideological elision of historical, structural perspectives,Footnote ³³ and an overbearing tendency to consider law from the mindset of what Judith Shklar famously critiqued as “legalism”: the “ethical attitude that holds moral conduct to be a matter of rule following, and moral relationships to consist of duties and rights determined by rules.”Footnote ³⁴ In this way, European law remains caught in the functionalist teleology of systems integration, even as its inadequacy to the deeper demands of solidarity is laid bare.

Somek’s critique does not itself offer a response to this problem. Nevertheless, it does encourage a more dynamic and diachronic attentiveness to how public perception of solidarity may be altered—and degraded—by certain attempts to realize post-national legal principles. He draws attention to how such realizations might in fact threaten to unravel the very notion of law as a source, not just of coordinated action, but of normative social integration. Somek’s work is therefore a call to consider more carefully how post-national law might yet avoid this compromising entanglement with neoliberal individualism and a too shallow conception of systems-thinking. If, as Hauke Brunkhorst writes, “[s]olidarity dialectically combines opposites, contradictions, and differences” and therefore might serve as a “bridge between the different modes of social and systemic integration of society,”Footnote ³⁵ this dialectic remains an unfinished project in European Union law.

It poses again the question, tabled by Havel and Agamben above, of how we might differently conceive solidarity’s place as a meaningful structuring principle of constitutional law, which would accordingly guide public interpretations of state competencies, shared obligations, determinations of jurisdiction and standing, and the scope of legal rights. How might solidarity intertwine social integration with social transformation anew in order to “modulate” the nature of state action and the kinds of considerations it reflects? If Article 2 TEU does indeed constitute a new “constitutional paradigm” with solidarity as a central principle to “transform existing legal relationships” and to “shap[e] and direct[] other core values and legal institutions,”Footnote ³⁶ what are its features and how might it do so?

The enduringly elusive nature of solidarity—even in times of crisis—reflects a need to scrutinize and perhaps revaluate the imagined theoretical grounds of legal solidarity at once in European Union law and in European constitutional theory. Therefore, I aim to use theory to make sense of legal developments and, in turn, to use legal developments to make sense of theoretical claims—and hopefully to offer new ways to think about each. I turn my analysis to mutual trust, in particular, because it perhaps reflects most directly the structural ambition to see legal ties as the basis for solidarity, and because it, too, reflects the lasting, path-dependent legacies of European market integration.

Mutual trust transposes concepts and symbolic understandings from the EU’s internal market-oriented policies to its ambition to create a space of other kinds of freedom and security, as well, and—perhaps most of all—to its relations with those who come to claim protection at its borders. Whether this transposition is successful and what it reveals about the ongoing struggles for solidarity through law are the subjects of the remaining sections.

C. Mutual Trust Through the Lens of Constitutional Patriotism: Solidarity and its Preconditions

As Brunkhorst has elaborated in his treatment of the idea, civic solidarity demands (a) a fully politicized conception of the people again “in purely legal terms as the totality of those subject to law”;Footnote ³⁷ (b) a clear connection to the universalizing logic of human rights;Footnote ³⁸ and (c) an emphasis on the inclusion of these affected legal subjects in the process of legislation, that is, in a human right to democracy with a “strict identity of the ruling and the ruled.”Footnote ³⁹ This perspective provides an account of legal order as the medium in which solidarity is to take shape, even absent a post-national demos with thicker social ties to underwrite citizens’ participation. Here, a global legal community (globale Rechtsgenossenschaft) creates a legal ethos and commitments to the effective protection of rights as conditions in which reciprocal responsibilities can be formulated and realized.

Here, Brunkhorst is indebted to a Habermasian discourse theory of law and, specifically, to Habermas’s understanding of “constitutional patriotism” as a way to ground national identity in universalistic civic ties through the binding nature of the rule of law. Insofar as solidarity is mediated by attachment to constitutional principle, it always potentially extends to new citizens, territories, and forms of recognition.

The development of constitutional patriotism spans Habermas’s early writings on post-war German political identity to his contemporary efforts to ground a European political culture beyond the nation-state.Footnote ⁴⁰ Habermas recognizes that a legal system of rights protection “must be enduringly linked with the motivations and convictions of the citizens, for without such a motivational anchoring they could not become the driving force behind the dynamically conceived project of producing an association of [free and equal] individuals.”Footnote ⁴¹ Yet, Habermas has also made it clear that any theories that derive such anchoring from the “ambivalent bonding force of archaic institutions” are wedded to the now utterly discredited “metasocial guarantees of the sacred.”Footnote ⁴² Therefore, it is constitutional patriotism—as the form of motivational affect directed towards constitutional principles themselves—that serves to supersede the particularist tendencies of pre-political ethnic-nationalist recognition, attaching instead—ultimately—to universalist rights and norms embedded in constitutional law.Footnote ⁴³ Constitutional patriotism hopes to offer a procedural basis for social cohesion and identity-formation within a post-metaphysical, pluralistic polity.

On this reading, solidarity is one of “the results or the ‘product’ of constitutional patriotism”: in Habermas’s definition, “an abstract, legally mediated solidarity between strangers.”Footnote ⁴⁴ Solidarity is tied to the success and vitality of reasoning among citizens in the public sphere, secured by the co-original implication of private and public autonomy, by both liberal and republican participatory rights.Footnote ⁴⁵ Over time, this relationship of mutual and reciprocal participation assumes among citizens the structure of a shared constitutional project that exceeds the boundaries of national states and parochial political communities.

The premise is that constitutional patriotism can link together national communities without requiring or presuming an already formed and fully consolidated transnational demos, one that would make the ongoing work and negotiation of the terms of solidarity superfluous. Post-national solidarity refers to a kind of process that sits precisely at the point of this negotiation. So, too, with the EU’s principle of mutual trust.

In European law, the principle of mutual trust has been a foundation for the expansion of European community from the early judgments protecting the nascent common market. In the well-known judgment in Cassis de Dijon, the European Court of Justice obliged Member States to “trust” the legal practice of fellow states with regard to the lawful production and marketing of goods such that domestic protectionist measures would be unnecessary and thereby justifiably prohibited under the European treaties.Footnote ⁴⁶ “Mutual trust” in this sense was a reciprocal commitment of Member States to the “legality and quality of each other’s legal systems.”Footnote ⁴⁷ It was the corollary to the mutual recognition of what these systems produced—a mutual solidarity, however limited to economics its essential terms were.

While in the first decades such principles meant primarily to protect the free movement of goods and services, the principle of mutual trust soon became vital for the cooperation of European states in matters of criminal law and, ultimately most germane for our purposes, immigration law, as well. Indeed, as the powers of the EU expanded in the “area of freedom, security, and justice” (AFSJ), mutual trust became a key mechanism for judicial cooperation reflected in the Tampere Conclusions of 1999 and later in the Stockholm Programme of 2009 concerning citizenship, security, asylum, and immigration policy.Footnote ⁴⁸

Mutual trust under the AFSJ, even more so than the mutual recognition of goods and services, creates a political and institutional space that approximates a post-national legal community, structured by the rule of law and the mutual affirmation of legal decisions taken elsewhere. While mutual recognition of goods and services enables cross-border flows and thus protects the rights of individuals in their private spheres, cooperation under the AFSJ entails giving mutual effect to judicial decisions. It affirms actions taken by representatives of a fellow Member State—whether decisions on claims to asylum or arrest warrants or other criminal sanctions—and thus by extension also affirms the opinions and decisions taken by that state’s citizens.Footnote ⁴⁹ The state “not only recognizes a law as being equivalent but recognizes the judicial act in its interpretation of all relevant provisions in a given case.”Footnote ⁵⁰ That decisions affecting individual liberty and fundamental rights can be enforced, and not merely that the “fruits” of other legal orders can be accepted, confirms the systemic legitimacy of those decisions in light of an implicitly shared set of procedural and substantive principles.Footnote ⁵¹ Citizens of the “trusting” state thus implicitly affirm the normative status of another’s decisions as their own. And, conversely, the state that means to be “trusted” evokes solidarity under the expectation that its own system of law can be affirmed by another as legitimate.

Mutual trust in this sense expresses the form of commitment we find in Habermasian constitutional patriotism. One’s allegiance across borders tracks the sound legal principles of fellow Member States. While different legal systems might indeed realize such principles in distinct ways, the affirmation of common, universalizing principles is enough to engender a binding and reciprocal relationship.

Like constitutional patriotism, mutual trust entails a necessary presupposition—a commitment to trust another’s interpretation of principle as legitimate and enforceable without mandating that one explicitly share in that particular interpretation. Here, normativity is affirmed formally without being recreated substantively in the individual case. Trust is secured in the first instance by reference to a shared legality alone. It is thereby a principle of agreement and forbearance at once. For this reason, Kalypso Nicolaidis describes mutual trust as a “horizontal transfer of sovereignty,” striking a negotiated balance that, on the one hand, “respect[s] sovereignty” by not requiring the complete harmonization of law and the centralization of authority and, on the other, “radically reconfigure[s] it” by “delinking the exercise of sovereign power from its territorial anchor.”Footnote ⁵²

Here, solidarity is a product of the relationship established by this transfer of sovereignty. But this solidarity rests on an unsteady ground. For there exists a well-known tension between the principle of a presumed mutual trust and the underlying prerequisite for that trust that comes from a certain level of explicit harmonization in the practices of Member States.Footnote ⁵³ Can there be trust, in other words, without harmonization? The shared commitment in mutual trust is predicated precisely on forgoing development of the same rules and standards across jurisdictions, thereby allowing national political and legal cultures a degree of freedom. As long as such national instantiations sufficiently reflect the same systemic principles, the broader integrity of the legal system is trusted. But the cooperative execution of another’s laws nevertheless suggests the need for some minimum level of harmonization and some form of agreement reflected in the particular practices of states. Mutual trust seems to require some underlying institutional “management” of its terms that exceeds the simple conformity found in formal principles of recognition.Footnote ⁵⁴

The solidarity implied and created by mutual trust in this regard represents a post-national legal principle—not a formal arrangement but a dynamic of interaction, a mode of governance that requires judgment about its own scope and limits.Footnote ⁵⁵ If solidarity here means a commitment to protect the agency of others, can we do so for those with whom we disagree, whose agency might undermine our own and might therefore undermine the efficacy of our principles as we have conceived them? Remember that constitutional patriotism aims precisely to supersede the particularist tendencies of pre-political recognition, attaching instead to the universalist norms of constitutional law. Thus the question here is not merely how to prevent mutual trust from violating one’s own principles but something deeper: On what ground are we to say such a violation is in fact illegitimate? With reference to whom, sensitive to whose concerns, and in what measure?

In posing the question this way, the principle of solidarity aims to make this tension in mutual trust productive. Assessments of mutual trust might in some instances create pressures toward explicit harmonization of laws but more broadly might, in the long-term, promote “judicial communication, mutual learning, and ultimately also approximation and trust.”Footnote ⁵⁶ Solidarity here acquires a dynamic insofar as it depends on the adjudication and enforcement of each particular case—with the understanding that each case attests to the broader systemic legitimacy of another’s rule of law and, in turn, bears in some way on the interpretation of one’s own legal commitments in the home jurisdiction. Each case occasions self-introspection, self-criticism, an understanding of another’s interests and how they might fit into one’s own, their impact in particular cases, and whether and why these abide by one’s principles. Over time, in other words, this process comes closer to forming a basis for a post-national constitutional project that might creatively expand the normative self-understandings of a common political community.

Constitutional patriotism imagines precisely this kind of “transformative conception of living together.”Footnote ⁵⁷ It shifts the understanding of political identity from an “unreflective” identification with particular national traditions to “dynamic and complex processes of identity-formation.”Footnote ⁵⁸ Constitutional patriotism is a “collective learning process,” in which “citizens see their constitutional culture as always open and incomplete.”Footnote ⁵⁹ Citizens attend, in other words, to the “refugees they are”—renegotiating the bounds and meanings of the political communities in which they seek to belong ever more fully.

Implicit, but central to the preservation of post-national solidarity under constitutional patriotism, is the idea that there is a “life of the law.” Habermas, in elegant and powerful prose, embraces this spirit:

Similarly, Nicolaidis writes that the way mutual trust is managed means it must also create “critical safeguards” that make it “progressive and flexible over time.”Footnote ⁶¹ This is perhaps the crucial hope of constitutional patriotism in the post-national context. If constitutional law can indeed be considered open in this fundamental sense, then competing polities might meaningfully intertwine their constitutional claims so as to support the kind of cross-border solidaristic commitments needed today.

Nevertheless, much hinges on how such processes of open-ended identity formation go forward, and more must be said about how democratic institutions and constitutional law might reflect them. And given the inadequacies of solidarity we find in Europe’s contemporary crisis, there is a misgiving that such normative hopes remain in crucial respects compromised by internal contradictions buried beneath their surface. The question remains whether the specific terms of Habermas’s hope for a “dynamic constitutionalism”Footnote ⁶²—as we see them reflected when the principle of mutual trust is put into practice—succeed in fully preserving this life of the law beyond the nation-state; and whether constitutional patriotism can indeed underwrite the kinds of political orientations, relationships, and subjectivities imagined by post-national solidarity.

D. The Dilemmas of Solidarity: The Dublin Regulation, Formal Recognition, and the Necessity of Critique

A key tension that structures both constitutional patriotism and mutual trust is this relation between universal norms in constitutional law and the particular ways they are interpreted, contextualized, and embedded in constitutional practice. The tension arises because it remains clear—either in the ambitions of mutual trust or in Habermas’s theory—whether the real attachment capable of sustaining trust is to the principles or to particular character of the social worlds that give principles their specific meanings. The nature and post-national possibilities of solidarity—precisely as the product of this attachment—thus very much depend on the objects of attachment we have in mind. Habermas writes in an important, but ambiguous passage that “[s]olidarity . . . arises out of law only indirectly, of course: by stabilizing behavioral expectations, law simultaneously secures symmetrical relationships of reciprocal recognition between abstract bearers of individual rights.”Footnote ⁶³ Such stabilization involves not merely abstract rights as elements of a democratic procedural consensus but also an understanding of the meaning of these rights as citizens live and invoke them in political practice. It thereby remains somehow related, if not entirely wedded, to certain communitarian dimensions of political life.

Indeed, after early criticism that he offered resources for too thin a political bond, Habermas modulated the relationship he envisioned constitutional patriotism could establish between universal principles of communicative rationality and a particular political-cultural tradition. No longer presuming a direct attachment to universal principles simpliciter, constitutional patriotism in this new light signified a more particularized and historicized attachment—to “the political order and the principles of the [German] Basic Law.”Footnote ⁶⁴ While Habermas never completely left behind his previous abstract formulations, his subsequent work immediately situated references to constitutional patriotism “within the historical context of a legal community”Footnote ⁶⁵ or simply within a “shared political culture.”Footnote ⁶⁶ The principles in positive law must be given, Habermas admits, a definite shape. He notes that “[t]he identity of a person, of a group, of a nation, or of a region is always something concrete, something particular.”Footnote ⁶⁷ It cannot “consist merely in general moral orientations and characteristics, which are shared by all alike,” but must instead present an “image” to oneself and others.Footnote ⁶⁸ To suture commitment to legal procedures, Habermas invokes a specified image of a people that is—at least for a time—unified, bounded, and fixed.Footnote ⁶⁹ The object of attachment, the means by which citizens feel bound and committed to the law and to one another, is this stabilization of expectations in light of a political culture of law that is historically and culturally specific.

Now, just as with the notion of mutual trust, if constitutional patriotism is to remain a source of solidarity that does not foreclose the universalizing character of law, this relationship to political culture must have rather distinct characteristics. While Habermas rules out the particularity of an ethnic or linguistic-cultural grounding for political commitment, a different sort of particularism does indeed underwrite the embrace of constitutional principles. The nature of the “shared political culture” must nevertheless be, as Habermas writes, dissociated from a “hegemonic majority culture” and “uncoupled from the level of subcultures and their prepolitical identities,” such that “different cultural, ethnic, and religious forms of life [can] interact on equal terms within the same political community.”Footnote ⁷⁰ This is what Habermas has in mind when he reiterates that, in post-conventional societies, “republicanism must learn to stand on its own feet.”Footnote ⁷¹ Thus, while solidarity grounds itself in particular allegiances to different constitutions with different interpretations of the catalogue of rights, such allegiance still engenders a consciousness of the universal. In the post-national context of mutual trust, “the same legal principles would . . . have to be interpreted from the perspectives of different national traditions and histories”Footnote ⁷² and brought into focus as part of a now transnational legal culture.

These formulations render unclear, however, what a “shared political culture” is meant to include. Specifically, what role is political culture meant to play in mediating law’s rational discourse, on the one hand, and the broader cultural meanings of the lifeworld, on the other? Consider, for example, what Habermas has written specifically about the future of a European public sphere and a supranational political culture:

This construction is curious for a number of reasons. First, Habermas accepts an analytic bifurcation of politics and culture, and ostensibly of constitutional principles and their broader social imaginaries. If this is so, it is unclear how citizens are understood to live out the common political culture and perceive it as something normatively valid or socially meaningful. This risks, again, conceiving of political commitment too “thinly.” Second, if we accept some kind of interrelationship between the thematization of political issues and their exploration in the broader cultural lifeworld, then the difference between the two scenarios Habermas identifies seems, in fact, to be quite minimal. As long as national cultural traditions remain “branched” in this way, then it seems likely that the vocabularies and languages used in the public sphere will be “culturally isolated” in the same manner, thus reducing the second scenario to the first.

These points are highly abstract, but return for a moment to the context of mutual trust. If a “shared political culture” must mean that the terms of mutual trust reflect an underlying consensus that such terms sufficiently accommodate the particular interpretations of law that are to be mutually affirmed, how can we distinguish this from an explicitly agreed convergence of mutually applicable standards? If mutual trust in fact becomes the latter, is the relationship still one of solidarity? Or does it instead become one of rule-following in a manner that opens or “modulates” national sovereignty much less creatively or transformatively from the perspective of post- nationality? Is it still the site of the kind of mutual learning post-national solidarity meant to engage as a balance of agreement and forbearance? And, conversely, if a “shared political culture” means that mutual trust does indeed remain highly formal and thin, then in what sense can mutual trust entail a solidarity that triggers critical inquiry into particular national practices—practices which can always mask power differentials that exclude without justification? Does it in this latter case simply become what Nicolaidis criticizes as mere isolated, “blind” trust?Footnote ⁷⁴ And if “shared political culture” of mutual trust reduces to either of these two scenarios, can it still sustain the kind of emancipatory mutual learning and “dynamic constitutionalism” as imagined?

There are thus two currents circulating beneath Habermas’s post-national constitutional project, and they flow against one another. Habermas certainly wishes for a kind of political culture that nests the particular historical experiences of nations in a certain manner within the universality of democratic principles. But in the examples and elaborations Habermas has offered, the idea of a “shared political culture” masks key contradictions as a substrate of post-national attachment. While Habermas is careful to avoid making a national political culture too particular—embedded too firmly in cultural social groupings—he perceives the particularisms of national constitutions and their historical interpretations of rights “more benignly,” as Robert Post and Reva Siegel put it.Footnote ⁷⁵ While the former threaten universal democratic principles and thereby require uncoupling, the latter comfortably give them concrete meaning without compromising their emancipatory orientation “one iota.”Footnote ⁷⁶ This seems to be the ambit, too, of constitutionalizing mutual trust in EU law. But—as we shall see with the example of the Dublin Regulation—the fear that such tension does in fact compromise the emancipatory orientation is significant, indeed.

E. Solidarity as Fallibilism and Responsiveness: The Structural Possibilities of the Particular Case

If the demands of legal solidarity cannot be captured adequately by recourse to the formalism of rule-following, what does this mean for the ways post-national solidarity might yet overcome the ideology of sovereignty as the orientation toward “mastery” or “control”? An essential lesson of the above dilemmas of mutual trust seems first to be that post-national solidarity requires a specific sensitivity—one focused on how the nature and structure of coercion are relational, systemic, and changing. In this regard, such sensitivity must track how perceived inadequacies in another’s law might always reflect inadequacies in one’s own law and how systemic failings structure one’s capacities and freedom. Such an orientation is a critical component for solidarity among peoples precisely because sensitivity to such processes complicates and resists the aspiration simply to act either on the formal presumption of agreement or on the basis of one’s own prerogative.

On this view, solidarity as a mode of legal integration cannot simply affirm a kind of loyalty codified by respect for the abstract rules of EU law. Instead, post-national solidarity—precisely as this dialectical, systemic critique—requires a certain kind of legal responsibility that reflects (a) terms of mutual dependency and mutual responsibility, and, just as importantly, (b) a dynamic responsiveness to how such responsibility evolves outside of one’s control and thus requires critical re-interpretation over time. This second element has been neglected in the cases above. But it is crucial for understanding the constitutional character of solidarity as a structure of political responsibility—responsibility for the ongoing decisions one is able to take and the grounds on which one takes them.

Violeta Moreno-Lax has recast the principle solidarity in the context of asylum law and Article 80 TFEU in terms of a “double-fairness”: fairness at once to the refugee applicant and to fellow Member States. It should “permeate the [Common European Asylum System] on a permanent, ex ante basis and thus guarantee[] cooperation and sharing of burdens in compliance with fundamental rights.”Footnote ¹⁰⁴ This is a persuasive, elegant interpretation of what is immediately, and in the first instance, needed as a matter of positive asylum law. But is it sufficient as an account of solidarity’s place in European constitutional theory more broadly?

Moreno-Lax’s application of Article 80 to the demands of the CEAS is relatively clear in its normative obligations; it creates a new framework for the equitable sharing of the burdens of asylum processing and for upholding fundamental rights standards. But it remains insufficient in the following respect: the assessment both of what it means to “share” burdens and to uphold fundamental rights is, as we have seen, a deeply contested and evolving affair. It implicates processes of judgment and questions of how one understands and interprets one’s normative obligations. The appeal to “fairness” as a moral category cannot presume, on its own, to resolve either underlying conflicts of interpretation or, with Markell, the underlying orientations toward “mastery” and efforts to isolate oneself from vulnerability that endure—even as states might come to agreements that go beyond narrow national self-interest. The structural imbalances, in other words, remain; and solidarity must aspire to more than a new formal rule determining the equitable distribution of asylum seekers.Footnote ¹⁰⁵

If solidarity as “double fairness” appears too positivistic to inform European constitutional politics, let me explore a complementary, though distinct formulation. We might instead see solidarity as a principle in the meaning of Herman Heller’s “fundamental ethical principles of law,” which provide “the doorway through which positively valued social reality daily makes its way into the normativity of the state.”Footnote ¹⁰⁶ Such principles, as David Dyzenhaus has explained, are “suprapositive in the sense of being beyond positive law, [b]ut they are not supracultural—they are principles which formulate the values embedded in our cultural practices which the Rechtsstaat institutionalizes.”Footnote ¹⁰⁷

Post-national solidarity would assume a particular meaning, with emphasis on the manner in which a community accepts the heterogeneity and differentiation of its world, how it approaches that world in the spirit of shared commitment. I mean this in two ways. First, solidarity describes cohesion with a view of its conditioning limit and with the consciousness that this limit is itself a contested site of politics. The boundary line is the foundation but also always the contingent result of (unpredictable) political action.Footnote ¹⁰⁸ Second, in addition to rejecting any “naturalized” closure of a polity’s terms of inclusion and recognition, solidarity recasts the manner in which a polity understands itself to act and, therefore, the image it has of its sovereignty. Sovereignty here refers not merely to the sociological capacity of the state for control—which has indeed diminished under globalizationFootnote ¹⁰⁹—nor to ultimate political authority, which, to the contrary, has remained as symbolically powerful as ever, but rather to the project of insulating oneself, asymmetrically and at the expense of others, from the shared vulnerability and pluralityFootnote ¹¹⁰ of the world. Solidarity in this light would scrutinize how disagreements among polities concerning their normative obligations might always reflect certain inadequacies in one’s own laws and in underlying systemic failings to equitably share not just responsibilities but also one’s vulnerabilities.