The discourse on European integration often revolves around asking what kind of political union the European Union wants to become. The answers vary widely. Some reach for the vocabulary of statehood outright, a federalist vision of a United States of Europe. Others conceptualise the Union as a federation: a political form with its own constitutional logic distinct from state and empire. The range runs further still, from rejecting the federal analogy altogether — whether through the sui generis thesis descended from the 1957 Stresa conference on the ECSC, or by conceptualising the Union through the lens of multilevel governance that relocated authority across levels — to arguing that Europe has acquired something close to federal-type legal authority while deliberately declining federal statehood itself. While the institutional models offered may differ, this piece focuses on an underlying thread running through all of them, the question on which many of their distinctions turn: who authorises deeper political union, and how, relatedly, is that authority generated?
The American experience is sometimes the imaginary that frames this debate. The constitutionalisation of Europe has long drawn on the language of American federalism, and moments of institutional innovation continue to be described as Europe’s “Hamiltonian moment”. Beneath these comparisons lie two competing conceptions of the authority underpinning federal arrangements: Does constitutional authority derive from a political community that already exists, or can it emerge through a shared commitment to a common future and in that process, creating a common society? These two possibilities have shaped competing readings of the American founding, and they continue to structure contemporary debates about European integration.
This short piece argues that these competing conceptions of constitutional authority — prior identity and mutual promise — remain visible in debates about the constitutional role of the Court of Justice and the idea of a European society. Yet the debate overlooks an important limit on what constitutional law, and particularly courts, can achieve. Through a brief engagement with Carl Schmitt and Hannah Arendt, I argue that if Europe is searching the American experience for lessons about deeper union, it should look less to the constitutional ingenuity of Philadelphia than to the continuing political work required to create and sustain the promises on which every constitutional order ultimately depends.
I.
The distinction between prior political community and mutual promise finds perhaps its clearest expression in two competing readings of the American experience. Signe Larsen reconstructs this divide through the constitutional thought of Schmitt and Arendt. The American constitutional system features in both their writings although they develop fundamentally different conclusions about the source of constitutional authority.
Schmitt argued that a constitution is not simply a collection of legal rules but the fundamental political decision through which a people determines the form of its collective existence. This formulation is premised on another important argument: that a people already exists as a political whole. Constitutional authority for Schmitt, therefore, derives from an already existing political community, while the Constitution merely gives institutional form to that underlying unity. It is for this reason that he understood the American federation as resting upon a political community that preceded the Constitution rather than one created by it. In Constitutional Theory, he argues that the question of sovereignty between the federation and its member states must remain permanently unresolved. A federation exists because two political communities coexist without either being fully subordinated to the other. If that ambiguity is resolved, the federation ceases to exist: if the federation prevails, it becomes a unitary state; if the member states prevail, the federation dissolves. Schmitt regarded this indeterminacy not as a defect but as the defining feature of a federation. Drawing on the American experience, and particularly on John Calhoun’s account of the Union, he understood the federal government as exercising delegated powers while sovereignty remained with the states.
This account of federation builds on Schmitt’s earlier claim that constitutional authority presupposes the prior existence of a people. If the Constitution does not create political community but merely institutionalises it, the federal compact can endure only where its constituent peoples possess sufficient political unity. It is for this reason that Schmitt repeatedly insists on substantial homogeneity among the constituent peoples of a federation. In The Nomos of the Earth, he reformulates the same intuition: the appropriation of land precedes legal order, and the demarcation of boundaries comes before constitutional agreement. In contrast, Arendt reverses this sequence. As Anna Jurkevics has argued, where Schmitt derives political order from an original appropriation of land – a taking that precedes and grounds all subsequent law – Arendt places promise before appropriation.
What holds a political community together, on Arendt’s account, is the making and keeping of promises rather than a prior claim to territory or a pre-existing people waiting to be recognised. Her account of federation follows directly from this understanding of constitutional authority. The defect of the Articles of Confederation, Arendt argues, was that they created the central agency of an alliance rather than a government. Because allied powers tend to cancel one another out rather than check one another, the arrangement produced political impotence rather than stability. Drawing on Hamilton, she argues that a confederacy of republics can overcome the problem of scale only where its constituent bodies constitute a genuinely new body politic rather than remain a mere alliance. On this reading, the Constitution was designed not simply to divide authority but to create a new political power capable of governing a large and expanding territory. Federation therefore enlarges, rather than diminishes, the political capacities of its constituent republics. Its deeper achievement, however, is that it abolishes sovereignty as the organising principle of the body politic. Properly understood, the federation has no internal sovereign because, for Arendt, sovereignty in political life ultimately collapses into tyranny. olitical plurality rather than homogeneity sustains the establishment and maintenance of a federation created in this way. It follows then, for Arendt, that the American federation succeeds because distinct political communities constitute a common political order while remaining, within that order, plural and equal. What is important to note for our purposes is that in such a configuration, constitutional authority arises through reciprocal commitments that establish and sustain a common world, rather than from an antecedent political unity.
It is worth noting that years before On Revolution, writing on the minority question in Europe, Arendt proposed a European federation with a common parliament in which minority peoples would participate as equals rather than as tolerated exceptions to a national majority. She later returned to the same institutional vision in advocating a binational Jewish–Palestinian state within a wider Mediterranean federation. Federation, on this account, is valuable both, because it creates political community through mutual commitment, and because it preserves plurality by preventing any single national majority from constituting itself as the sovereign of the polity.
II.
Juxtaposing Schmitt and Arendt on the location of authority in a federation brings into focus a question that continues to shape debates about European integration: whether constitutional law reflects an already constituted political community or participates in bringing one into being. The question has obvious implications for the judiciary, particularly in constitutional orders such as the United States and the European Union, where courts occupy a central constitutional role.
The American founding relies upon the judiciary rather than the executive as the guardian of the constitutional arrangement concerning federalism. In Federalist No.78, Publius famously described the judiciary as possessing “neither force nor will, but merely judgment”, making it the least dangerous branch. Worth noting that Madison’s original Virginia Plan would have empowered Congress to use force against non-complying states, but he ultimately abandoned the proposal, observing that coercion against a state would resemble a declaration of war rather than the execution of law. The Constitution instead entrusted the maintenance of the federal compact to judicial judgment. For Schmitt, however, this solution is mistaken: if a court is authorised to determine where the boundary between the federation and its constituent members lies, it also gets the power to decide where sovereignty lies. Contrary to Schmitt’s advice to leave the location of sovereignty in a federation ambiguous, in the American system, through repeated acts of interpretation the judiciary resolves the question that the federal compact was designed to leave open.
To Schmitt, the contours of the dilemma are clear: if constitutional authority derives from a political community that exists independently of law, judicial interpretation cannot substitute for democratic authorship without displacing the very source of constitutional authority. If, by contrast, constitutional authority emerges through the constitutional project itself, courts may plausibly understand themselves not only as interpreters of constitutional commitments but also as institutions that sustain them over time.
III.
Few constitutional systems make this question more pressing than the European Union. From the earliest accounts of European constitutionalisation, the Court of Justice has occupied an unusually prominent place in the construction of the European legal order. The Union’s constitutional development has often proceeded through judicial doctrine in the absence of a corresponding constituent moment. The question has therefore never been simply what the Court has decided, but whether judicial interpretation can itself participate in the construction of European political authority. The Court’s own President has repeatedly defended precisely this understanding, echoing Federalist No. 78: the Court is not political but pro-law; its authority derives from the Treaties and its task is interpretation rather than politics.
Recent debates surrounding the idea of a European society reproduce the competing conceptions of constitutional authority identified by Schmitt and Arendt. Armin von Bogdandy argues that European society is not primarily an empirical fact but a constitutional project. Public law embodies the promise of political community and, through that promise, participates in bringing European society into being. Constitutional authority therefore does not depend upon the prior existence of a European people. His critics object that a society reconstructed principally through treaties, judicial decisions and constitutional principles risks becoming indistinguishable from the legal order itself. If European society is visible only through law, constitutional authority becomes self-referential: law derives its authority from the society it is said to constitute, while that society is in turn identified primarily through law. Loughlin, for instance, expresses concern that constitutionalism of this kind elevates the founding document above ordinary politics and places its interpretation in the hands of legal elites, so that constitutional authority appears increasingly to emerge from within legal reasoning itself, as judges and scholars identify and develop constitutional principles rather than a political community authoring them.
This raises the question of whether constitutional authority can in fact be generated through legal interpretation and rationalist legal reasoning alone, or whether it must ultimately be grounded in practices of collective political authorship that law can stabilise but not itself create. A possible response in favour of Bogdandy could be that this misunderstands constitutional development: political communities are constituted rather than discovered and the absence of a pre-political European demos is therefore not an objection to constitutional integration but the very reason public law matters.
Yet Bogdandy overlooks an important feature of Arendt’s account of promising. For Arendt, a promise is a political practice through which plural actors publicly bind themselves to one another. Law may preserve, stabilise and enforce such commitments, but it can only operate on commitments already undertaken. In other words, promises should not be treated as constitutional aspirations waiting to be realised through judicial interpretation. A constitutional court can only work with commitments that plural actors have already made to one another.
IV.
The lessons and limits of the American analogy can now be stated. Contemporary European constitutional theory has largely adopted Arendt’s language of constitutional promise while relocating the work of promising from citizens to courts. The promise survives, but chiefly as an object of legal interpretation and in doing so, a relationship between judges and constitutional texts supersedes the relationship between citizens.
This marks an important limit of constitutionalisation as a strategy of political and social integration. Courts may recognise and preserve shared commitments, but they cannot author them. The more constitutional authority comes to depend upon judicial identification of shared commitments, the further those commitments risk becoming detached from the political practices that give them democratic legitimacy. A promise sustained primarily through legal interpretation is no longer quite the promise Arendt had in mind.
Seen in this light, the American experience offers a more complicated lesson than is often assumed. It certainly demonstrates that constitutional law can provide an enduring framework for political cooperation. But it also demonstrates the limits of constitutional design. Arendt was right to emphasise the importance of founding through mutual commitment rather than sovereign command. But the subsequent history of the United States also reminds us that constitutional promises did not sustain themselves. The constitutional settlement reached at Philadelphia did not eliminate political disagreement over the character of the Union. It postponed many of its deepest questions. The American republic was shaped through civil war, Reconstruction, westward expansion, the dispossession of Indigenous peoples, slavery and its aftermath, and the gradual construction of a national political identity. The relationship between the states and the federal government, the scope of federal authority and, most fundamentally, the identity of the American people remained subjects of profound contestation. Neither judicial interpretation nor constitutional ingenuity resolved those disagreements. Political unity proved to be not simply the product of constitutional promise but of continuing political conflict, institutional development and, often, violence.
The lesson for Europe is therefore not that constitutional law cannot contribute to political integration. It plainly can, and it has. The Court of Justice has transformed the constitutional landscape of the Union more profoundly than almost any other European institution. The difficulty is a different one. If Europe is to build a deeper union, the decisive work lies not in judicial innovation but in the continuing political practice of citizens undertaking and renewing commitments to one another. If Europe continues to look to the United States for constitutional guidance, it should therefore resist the temptation to treat Philadelphia as a blueprint for constitutional design. What the American experience reminds us of is that constitutions do not relieve citizens of the work of politics; constitutions merely create a framework within which that work must continue. That is the lesson the American founding left open, and it is one Europe cannot avoid as it once again asks what kind of political union it wishes to become.
