Some twenty-five years ago, John Ruggie defined “multilateralism” in terms that remain apposite today. As an international lawyer, this definition prompts me to reflect on the connections between the international legal order and multilateralism. To be sure, international law has unilateral, bilateral, and multilateral features, for example in lawmaking or law enforcement.Footnote ² Similarly, it can be wielded to unilateral, bilateral, or multilateral ends. Indeed, it is precisely because it transcends ends and issue areas, that international law, by providing “generalized” principles of conduct and interaction, is an important component of multilateralism.

International law's generalized principles include those that define what counts as “law,” along with basic concepts such as sovereignty, non-intervention, or the prohibition on the use force. These precepts have served to accommodate diversity and pluralism, much as Ruggie's definition suggests multilateralism does. It stands to reason that it is precisely the trait of generality that has enabled international law to anchor the many multilateral institutions that have grown into and endured as forums for addressing a wide range of collective concerns. The importance of generality, and of a shared notion of legality, rests not only in providing a platform for the elaboration of common purposes, but perhaps most of all in enabling and guiding ordered interaction in their absence, or even in the event of conflict.

Over the last one hundred years or so, certainly since World War II, the basic features of a universal conception of law (as opposed to specific norms within the legal order) have remained largely unchallenged.Footnote ³ In turn, multilateralism has been the dominant modus operandi of the post-World War II international order. At the current juncture, however, both multilateralism and the international legal order seem to be under siege. The rising pressures on each are a result of an amalgam of long-standing and more recent factors.

To some extent, the current dynamics might be understood as a recalibration after the (perhaps inflated) optimism of the early 1990s. In that sense, we are witnessing a reckoning with undue assumptions about common purposes, common values, and shared norms. It may also be the case that the more forcefully that multilateralism was deployed in the name of liberal internationalism, the more tenuous it became over time. At any rate, history did not end with the fall of the Berlin Wall.Footnote ⁴ The upswing of multilateralism in the early 1990s may well have been the high point of what was achievable, because the shared ground on which to build was much more limited and more fragile than it seemed.Footnote ⁵ Historical grievances have continued to simmer in large parts of the world regarding the preferences and inequities baked into both multilateralism and international law.

These fractures and frailties may not have been apparent (or were overlooked) as long as Western states, and notably the United States, were able to shape and drive the international agenda, as they had done since the end of World War II. After all, in reconstructing the post-war international order, the United States actively promoted multilateralism as the governance principle: in international security through the United Nations and the North Atlantic Treaty Organization in trade through the General Agreement on Tariffs and Trade (and later the adoption of World Trade Organization Agreements), and in countless other contexts, such as environment, health, or migration, seeking to build multilateral institutions around its preferred general organizing principles.Footnote ⁶

The diversification of international society—both through the emergence of new states with vastly different needs, capacities, priorities, and outlooks, and through the rise of business and civil society actors and terrorist networks—posed a series of challenges to this agenda. Although the changes in the makeup of international society prompted efforts to adapt and develop international law in response, until recently, it nonetheless was business more or less as usual in international affairs.

So, what has changed? Why is the international order at a crossroads now? In my view, the current crisis—for that is what I believe it is—is fueled by the confluence of two major dynamics.Footnote ⁷

First, we are witnessing the rise of major regional or even global powers outside of the West—China, India, Iran, Saudi Arabia, and Turkey among them, along with a resurgent (or at least increasingly aggressive) Russia. Some of these states, notably China and Russia, are explicitly championing a new global order. Russia is seeking to promote a “post-Western world order,”Footnote ⁸ while China prefers a more neutral label—a “new world order.”Footnote ⁹ Labels aside, China and Russia agree on the core features of the desired order. In a 2016 joint declaration on the “promotion of international law,”Footnote ¹⁰ the two countries articulated a thin conception, focused on the UN Charter and emphasizing sovereignty-based principles like non-intervention or state immunity. In a sense, the goal is a return to a law of coexistence, stripped of liberal internationalism and its emphasis on human rights.

Ironically, however, the most potent challenges to multilateralism and international law do not come from increasingly assertive non-Western powers, but from within the West. Notwithstanding the fact that, by and large, Western countries have been beneficiaries, shapers and defenders of the existing international order, a backlash has erupted in many Western states against the perceived reach and intrusiveness of international law and institutions.Footnote ¹¹ This backlash is driven in part by economic concerns, including the uneven distribution of the fruits of globalization, valid concerns that have boosted the political fortunes of self-styled “populist” leaders.Footnote ¹²

By far the most destabilizing challenges to multilateralism come from the United States.Footnote ¹³ Since the inauguration of President Donald J. Trump, the U.S. government has adopted an increasingly unilateralist, transactional posture.Footnote ¹⁴ Indeed, accumulating actions, including the administration's recent moves toward “trade wars” with other major economies,Footnote ¹⁵ the refusal to sign on to the traditional G7 Summit communiqué,Footnote ¹⁶ the withdrawal from the UN Human Rights Council,Footnote ¹⁷ and the promised withdrawal from the Paris climate agreement,Footnote ¹⁸ suggest that the United States has turned against multilateralism. Even more disconcerting is the growing string of instances in which the Trump administration appears to question fundamental precepts of international law, such as the rights of refugees from conflict zones, the prohibition on torture, the prohibition on the use of force, or the rules of the world trading system.Footnote ¹⁹

If in fact the United States is wavering in its long-standing commitment to the international rule of law, as many observers fear,Footnote ²⁰ this turn would be momentous. It would mean that, for the first time since World War II, a major state would challenge not only the content of specific legal norms and regimes, but the very foundations of an international rule of law—the aforementioned “generalized” principles that allow for a thin but universal conception of international law.Footnote ²¹ There would be bitter irony in the fact that the major state in question is the very state that led the world in building and maintaining the post-war multilateral order.

The historical significance and the future implications of these developments are not lost on other Western leaders. France's president signaled his intention to step into the global leadership gap,Footnote ²² notably on climate change.Footnote ²³ The German foreign minister, shortly after the U.S. president's unprecedented refusal to endorse the June 2018 G7 Summit communiqué,Footnote ²⁴ laid out a detailed vision for a “Europe United” as an answer to “America First.”Footnote ²⁵ On the same day, his Canadian counterpart delivered a major foreign policy speech to underscore the importance of the “rules-based international order and the postwar institutions built to maintain it.”Footnote ²⁶ It is as yet uncertain whether these efforts to rally support for multilateralism and international law will suffice to prevent the unravelling of the global order. Equally uncertain is to what extent non-Western states, notably China, will be partners in maintaining a “rules-based international order.”

It seems that, one way or another, we are witnessing a transformation of the global order. If President Trump succeeds in promoting an America First, transactionalist order, post-World War II multilateralism might simply atrophy. Assuming that multilateralism prevails in some form, the world may be moving to a leaner multilateralism, increasingly anchored in norms that are promoted and shaped, or at least co-shaped, by leading non-Western states. As several colleagues have recently illustrated, international law does need to do better in reflecting globally shared norms.Footnote ²⁷ If the current crisis prompts a shift to an international order built around such norms, it might end up strengthening both the reach and the influence of international law. Multilateralism might yet have a future.