This post is an advance version of a review essay that will appear in Humanity volume 10. It will be posted in five parts: one each day this week. This is part 2.
Hathaway and Shapiro announce in their introduction that “this book is, at its core, a work of intellectual history” (xx). I am not sure that this does justice to the ambition of their project, which is much larger. In their conclusion, they summarize its essential point as the insight that “the choice between law and power is a false one. Real power…does not exist in the absence of law” (422). This claim is not primarily a historical one, although it would be readily accepted by the mainstream of the historical profession. For intellectual historians the recognition that norms, laws, and other ideas matter is the starting point of inquiry, not its conclusion. Rather, the claim that the law and international norms weigh as heavily as power is a theoretical point about the nature of politics and international affairs. The book’s underlying message therefore seems to be intended primarily for an audience of political scientists, scholars of international relations, and policymakers. Indeed, this is what has been picked up by most reviewers, both positive and negative. Yet for historians The Internationalists is more interesting as a work that shows how legal orders develop over time. Such historicizing of norms shows not only that they are amenable to purposive change, but also that the past can provide imaginative resources for improving them further.
Most intellectual histories of international law that focus on the mainstream of international lawyers are concerned with ius in bello, the laws that govern the conduct of war. In this context, the effort to limit the cruelty of warfare (for example by banning the use of certain weapons or protecting prisoners) was always a tacit acceptance of the normality and legality of war in general. Hathaway and Shapiro’s notion of the Old World Order helps us understand why so few jurists between the seventeenth and twentieth centuries asked whether war should be waged at all. Most were concerned by the question of what constituted legitimate reasons for doing so. This question had been the traditional concern of just war theorists and the resulting legal rules were often referred to as ius ad bellum. Just war theorists operated with various definition of legitimate war. Some saw armed intervention in the name of humanity or civilization as permissible when cruelty against civilians and non-combatants was taking place. Others thought that the only valid reason for taking up arms was self-defense.
Hathaway and Shapiro show that the outlawry movement led by Levinson and Shotwell was a movement to end war tout court that subscribed to the latter view. Shotwell wanted to distinguish between aggressive wars and defensive wars. Levinson opposed this distinction. He saw the right to defend oneself against external attack as elementary. It was an “inherent and ineradicable as a naked right,” and impossible to define clearly in any case (123). Interestingly, Levinson’s view that self-defense was so basic a right that no state or individual could ever sign it away in a treaty resembled the philosophy of Grotius, for whom self-preservation was the primordial right from which all others could be derived. As a result, neither aggression nor self-defense was defined substantively in the 1920s. This lack of consensus would prove highly consequential for the remainder of the twentieth century, as states increasingly justified wars and the use of force by invoking self-defense.
One important interpretative question raised by The Internationalists is how to make sense of the Kellogg-Briand Pact in relation to the history of international organizations created to safeguard peace, the League of Nations and the United Nations. Hathaway and Shapiro view the League of Nations created in 1919 as a “reprieve” of the Old World Order because “to solve the problem of war” it prescribed “more war” (106). By contrast, they see the United Nations as the “embodiment” of the New World Order (213). If this is true, then the essential differences between the two world orders would be reducible to the differences between the League Covenant and the UN Charter. This is a big claim that is difficult to maintain without qualification. First, though the League did not ban war as such, it was obviously opposed to wars of conquest. Once in session it did not endorse land-grabs unsupported by plebiscites, petitions by the local population, or intergovernmental agreement. Initially, the practical difficulty for the internationalists convening in Geneva was that from 1917 to 1923, much of Eastern Europe, Russia, and the Middle East were engulfed in a series of civil wars, secessions, state collapses, revolutions, and inter-state wars. Territorial changes resulting from this long, bloody aftermath of World War I did not solidify until 1921. But thereafter, conquest pretty much ceased for a decade (this virtual vanishing of conquest in the period between 1921 and 1931, most of it before Kellogg-Briand came into effect, is an important detail that I will return to later, when discussing the empirical data used by Hathaway and Shapiro).
The second issue with positing a radical break between League and UN is that most historical analysts have tended to emphasize the continuities between the two organizations rather than their differences. Article 10 of the Covenant protected against “external aggression the territorial integrity and existing political independence” of its members; in the Charter this provision is contained in Article 2.4—the only difference is that the predicate “existing” has been dropped. If the banishment of wars of aggression is the essential hallmark of the New World Order, then its roots were already firmly present in the League of Nations, a decade before the ratification of the Kellogg-Briand Pact, whose three short articles mention war but not aggression.
Several treaties in the 1920s tried to abolish war and preserve peace between states. Hathaway and Shapiro devote two pages to the Geneva Protocol for the Pacific Settlement of International Disputes, drafted by the League in 1924. Intended as a document to clarify the outstanding interpretative disputes about the Covenant, this treaty forced states to submit all disputes to arbitration by the Permanent Court of International Justice (PCIJ), which had started hearing cases in 1922. Article 2 committed signatories “in no case to resort to war with one another…except in resistance to acts of aggression or when acting in agreement with the Council or the Assembly of the League of Nations.” All the essential elements of the New World Order—mandatory recourse to peaceful dispute resolution, the criminalization of aggression, and international outcasting through economic sanctions—were present in the Protocol.
In 1924, James Shotwell and several other American internationalists had drawn up a plan for disarmament and arbitration premised on the criminalization of aggressive war. Hathaway and Shapiro rightfully recover this forgotten plan from historical oblivion. Yet their claim that the Geneva Protocol “emerged from the American plan” is misleading (117). Its preamble, which explicitly called aggression an international crime, was taken from the Shotwell plan. But the actual document was largely a European creation, based on proposals by British and French prime ministers Ramsay MacDonald and Edouard Herriot that were subsequently worked out by the Czech Foreign Minister Edvard Beneš and the Greek jurist Nicolas Politis. The Europeans appreciated Shotwell’s input, but the eventual treaty went so far in its hermetic and mandatory sanctions that Shotwell himself would come to reject it. By framing the outlawing of war almost entirely as an American accomplishment, Hathaway and Shapiro gloss over the contributions made by internationalists elsewhere in the world, and misconstrue why the Geneva Protocol failed where Kellogg-Briand succeeded.
The Internationalists argues that the Protocol failed because it was legally incoherent: to preserve peace it forced signatories to impose economic sanctions against aggressors, but under the Old World Order such measures provided grounds for war. Hathaway and Shapiro claim that “in a world in which sanctions were still a cause for war, outlawry backed by sanctions did not offer an end to war but simply a new path to it” (119). This interpretation takes at face value the legal problem that London and Washington raised, but it ignores that the procedural was a useful cloak for the political. Many jurists at the time saw the theoretical issue as much smaller than portrayed. David Hunter Miller, the lawyer who had collaborated with Shotwell on both the League Covenant and the 1924 plan, pointed out that the Protocol made the sanctions mechanism “more flexible in its application.” It gave “any signatory State called upon to apply sanctions the privilege of exercising the rights of a belligerent, if it chooses.” But the designation of an aggressor and the imposition of an international blockade did not, by itself, create a state of war. The sanctioning states could declare war, but were not obliged to do so. For the United States, then, there would be no ground to fear foreign interference with its external trade. As Miller put it, “any resulting blockade was not applicable to the United States…and this view would be accepted by the members of the League as being legally sound.” After all, during World War I an Anglo-French blockade of the Central Powers had also restricted the commerce of many neutral states, sometimes very severely, all without causing a war with them. As we shall see, the innovative aspect of economic sanctions after the Great War was that they were a non-belligerent practice, allowing the legal use of coercion outside of war.
Hathaway and Shapiro are right that the Protocol interfered with an element of the Old World Order. But for the United States the really longstanding principle at stake was not the legality of war but the Monroe Doctrine. President Coolidge and Secretaries of State Charles Evans Hughes and Kellogg did much to stop the treaty because it threatened to interfere with the 102-year-old U.S. claim to hegemony in the Western Hemisphere. The Protocol promised League solidarity with Latin American countries in case their sovereignty was violated. This is why Hughes called it “a new Holy Alliance”: it would allow European and Asian countries to assist Latin American states in asserting their independence. The history of the Geneva Protocol in 1924-1925 shows that the United States (like Britain) was only prepared to support a ban on war when it could decide on the terms, and cast them into a definition and structure that would preserve its supremacy over smaller countries.
 Margaret Macmillan, “The Internationalists by Oona Hathaway and Scott Shapiro—Law and Peace,” Financial Times, September1, 2017, available at: https://www.ft.com/content/9e4191c6-8db5-11e7-9580-c651950d3672. Max Boot, “When the Governments of the World Agreed to Banish War,” New York Times, September 21, 2017, available at: https://www.nytimes.com/2017/09/21/books/review/the-internationalists-oona-hathaway-scott-shapiro.html. Stephen Walt, “There’s Still No Reason to Think the Kellogg-Briand Pact Accomplished Anything,” Foreign Policy, September 29, 2017, available at: http://foreignpolicy.com/2017/09/29/theres-still-no-reason-to-think-the-kellogg-briand-pact-accomplished-anything/
 Robert Gerwarth, The Vanquished: How the First World War Failed to End, 1917-1923 (London: Penguin, 2016).
 See, for example, the interpretation of Mark Mazower, Governing the World: The History of an Idea, 1815 to the Present (London: Penguin, 2012), chap. 5.
 “Protocol for the Pacific Settlements of International Disputes, Adopted by the Fifth Assembly of the League of Nations on October 2, 1924,” 1.
 Carl Bouchard, “Le ‘plan américain’ de Shotwell-Bliss de 1924: Une initiative méconnue pour le renforcement de la paix,” Guerres mondiales et conflits contemporains, no. 202-203 (2001/2002): 203–25.
 The best account of the British role in the creation of the Geneva Protocol is in Peter Yearwood, Guarantee of Peace: The League of Nations in British Policy 1914-1925 (Oxford: Oxford University Press, 2009), 282–325. For a wider European view of the episode see Zara Steiner, The Lights that Failed: European International History, 1919-1933 (Oxford: Oxford University Press, 2005), 380–94.
 David Hunter Miller, The Geneva Protocol (New York: The Macmillan Company, 1925), 75.
 Ibid., 93.
 For a complete account of U.S. involvement in the (failure of) the Protocol, see David D. Burks, “The United States and the Geneva Protocol of 1924: ‘A New Holy Alliance’?,” American Historical Review 64, no. 4 (July 1959): 891–905.