The Peace of Westphalia as a Secular Constitution

“Westphalia” is often used as shorthand for a system of equal and sovereign states; and the peace treaties of Westphalia, concluded in 1648 at Munster and Osnabruck and ending the Thirty Years’ War, are sometimes said to have established the modern concept of sovereign statehood. The distinguished international relations scholar Stephen Krasner, while commenting that this model “had virtually nothing to do with the Peace of Westphalia,” nonetheless defines as “Westphalian” an “institutional arrangement for organizing political life that is based on two principles: territoriality and the exclusion of external actors from domestic authority structures.” According to Krasner, “Westphalian sovereignty is violated when external actors influence or determine domestic authority structures.” Krasner explains that he chooses to use this terminology because the “Westphalian model has so much entered into common usage, even if it is historically inaccurate.”1 As Krasner notes, among the possible meanings of “sovereignty” there is a further, closely connected yet slightly different meaning he refers to as the “international law definition” of sovereignty. International legal sovereignty is concerned with “establishing the status of a political entity in the international system,” i.e. a state is regarded as sovereign when it possesses international legal personality and is a subject of international law, a necessary condition for entering into treaty agreements with other entities.2 This is a notion of sovereignty that is based on an analogy between states and individuals, deriving its force from the application of liberal political theory to the international realm. It is obvious that “Westphalian” sovereignty and international legal sovereignty are conceptually independent from each other – it is conceivable that one can be had without the other. Indeed, sovereigns in the international law sense can voluntarily compromise features of their “Westphalian” domestic sovereignty, and sovereigns in the so-called Westphalian sense need not necessarily have international legal personality.3 However, much scholarly literature on the history of international law and international relations claims that both the “Westphalian” and the international law notion of sovereignty have their origin in the Peace of Westphalia.4 In this paper I seek to shift the focus from this popular conception of the peace treaties of Osnabruck and Munster, and instead treat them as constitutional documents, relevant to the historiography of international law and international affairs in a different way from the more established usage. In this I join a small but growing body of work on constitutional aspects of the Peace of Westphalia, research thus far conducted more by lawyers and political scientists than by historians.5 A significant example of recent public law scholarship in this vein is Roderick Hills’ stimulating essay “Federalism as Westphalian Liberalism.”6 Hills, a prominent American public law scholar, sets out to claim the constitutional arrangements of the Peace of Westphalia for the liberal tradition. His essay adduces Westphalia as a model and successful historical example for one particular kind of federalist constitutional structure. There is a normative implication in Hills’ argument, namely that Westphalia serves as an experiment well worth emulating.