This book tells the fascinating story of how the works of Alberico Gentili (1552–1608) were re-appropriated by international lawyers during the late nineteenth century and by Carl Schmitt in the twentieth in support of a narrative telling us how the right to war had become the prerogative of sovereign states to the exclusion of other actors. This canonization of Gentili produced one the most persistent myths in the study of international law and international relations, one with profound implications for the ways in which the laws of war have been understood and justified in the modern world.

To explain how this myth was constructed and gained traction, Claire Vergerio first situates Gentili’s De iure belli (1598) in its original context to convey a sense of what Gentili intended to achieve and how his work was received by his contemporaries, before proceeding to examine its re-appropriation by late nineteenth-century international lawyers in defense of the scientific status of their discipline, the emerging world of sovereign states, and new practices of imperial warfare. But the real villain of the story is Carl Schmitt, whose selective uptake of De iure belli allowed him to portray the transition from a medieval conception of war as law enforcement or punishment to a modern conception of war as a contest between legal and moral equals as a commendable step in the taming and humanization of war that he took to be characteristic of early modern absolutist states, all while legitimizing his own preference for authoritarian rule in the process. As the author contends, it was from his Nomos der Erde (1950) that this myth trickled down to eventually become a commonplace of the modern study of international law and international relations.

Its remarkable erudition and meticulous attention to detail make War, States, and International Order an outstanding piece of scholarship, situated where the concerns of legal history, history of political thought, and international relations intersect. Skillfully combining insights from all of these fields, Vergerio argues that the impulse “to associate the restriction on the right to wage war exclusively to sovereign states with the stabilization of international order rests on an erroneous historical narrative about modernity, the emergence of the states-system, and the taming of war” (p. 19). In doing so, she joins forces with a growing number of scholars who have questioned received interpretations of past authors in favor of fresh contextualization, thereby frequently exposing abysmal discrepancies between their original meanings and those ensuing from later appropriations, often as a result of being informed by present ideological concerns. Inaugurated by Cambridge historians like Quentin Skinner, such myth-busting has evolved into a cottage industry within the human and social sciences today, nourished by the conviction that setting the historical record straight—that is, purging it of anachronism—is a necessary precursor to a better understanding of present problems, unclouded by distorted views of the past.

Although War, States, and International Order accomplishes this with great panache, the book also indicates the extent to which the practice of myth-busting has come to resemble a whack-a-mole, with the busting of one myth followed by sowing the seeds of another. A case in point concerns the historical origin of the sovereign state and the modern international system. While students of international relations and law have long been in the habit of locating the emergence of these to the mid-seventeenth century—in the textbook version to the Peace of Westphalia in 1648—recent scholarship has shifted attention to the long nineteenth century, with the consolidation of state power and the spread of nationalism as benchmark indicators of a world of nation-states in the making.

War, States, and International Order itself partakes in this shift by arguing that the late nineteenth-century appropriation of De iure belli was conditioned by rise of “the modern nation-state understood as a unitary authority with control over a linear and homogenous territory and a much stricter monopoly over the use of force than ever before” (p. 210). This was “a form that would have been entirely unimaginable for the likes of Gentili” (p. 197), who had drawn extensively on Jean Bodin to locate supreme authority and the right to wage war in the person of the sovereign, and on authors in the ragion di stato tradition to make sense of the intercourse between such sovereigns in terms of interest and power. The later appropriations of De iure belli and the corollary contention that war was the sole prerogative of sovereign states were made possible only by ignoring the differences between these conceptions of sovereignty.

Although it is true that early modern authors were characteristically vague when it came to the scope of sovereign authority—struggling as they were to accommodate a wide variety of polities—it is possible to argue that some (notably Botero and his followers) also were invested in its depersonalization by trying to conceptualize polities in terms independent of rulers as well as ruled. That Gentili comes across as an absolutist in De iure belli is understandable, not only because of his appropriation of the works of Jean Bodin, but even more so considering that monarchy was the default form of rule at that point in time. But Gentili also spoke of nations (gentes) as legal entities that enjoyed a transhistorical life independently of sovereign authority. Such underlying continuities in the ways in which political authority and community were understood in the early modern and modern periods make the broader claim of War, States, and International Order appear somewhat overstated, since it is fully possible to examine how sovereignty and war have been conceptualized across these periods without thereby subscribing to the distorted views of Gentili promulgated by authors like Thomas Erskine Holland and Carl Schmitt.

When Carl Schmitt appropriated De iure belli, he did so by drawing a sharp distinction between what he took to be a medieval understanding of war as law enforcement or punishment, and credited Gentili with having inaugurated a modern understanding of war as a contest between equals. However, this distinction, along with the spurious periodization upon which it rests, can be questioned by pointing out that war in the former sense was to remain a going concern in the making of the modern international system throughout the early modern and modern periods. The nebulous enterprise devoted to its justification—rebranded “international law” by Jeremy Bentham—came to depend for its seeming continuity and coherence on the imagined existence of a constitutive outside populated by a host of family-resemblant Others, of which the pirates, brigands, and rebels singled out for target practice by Gentili were but the first, with all those excluded from the purview of sovereign statehood and international recognition in the waiting room.

War, States, and International Order does an excellent job in exposing how the selective appropriation of Gentili has contributed to the occlusion of this genealogy of international order. Pursuing this inquiry further would require moving beyond myth-busting and venturing deeper into the longue durée of international legal theory and practice.