For the last decade or so, a debate has raged among scholars and policymakers about the significance of the post–World War II, rules-based international order. Is it a feeble myth, as Graham Allison has suggested in Foreign Affairs? Or, as G. John Ikenberry and others have argued, is it a powerful influence on state behavior?

Russia’s invasion of Ukraine and the global response to it has put these competing claims into sharp relief, underscoring that the postwar order places real and tangible constraints on most countries. But the war has also made clear how brittle international orders can be and highlighted two potentially fatal vulnerabilities of the current one: excessive ambition on the part of dominant powers and careful hedging on the part of middle ones. These weaknesses may have put the postwar order and the legitimacy of U.S. leadership in more danger than at any time since 1990—and preserving them will require walking a difficult diplomatic tightrope.


Broadly speaking, the international order is nothing more than the prevailing pattern of interactions in world politics. The existence of an order does not presume shared, enforced rules or any degree of stability. But in certain periods, rules-based orders have emerged that benefited many nations. These systems were not grounded in altruism or the ideal of a supranational government. Rather, the most powerful actors of the era, often under the leadership of one preeminent power or a small number of them, agreed to certain explicit or implicit rules and norms to promote their own interests—typically, territorial security and economic prosperity.

The post-1945 U.S.-led international order is by far the most institutionalized rules-based order to date. It is grounded in the UN system but incorporates regional organizations such as NATO and the European Union, as well as global economic institutions, intergovernmental processes, public-private coalitions, and nongovernmental organizations that set thousands of issue-specific rules and standards. The order embodies norms, imperfectly adhered to but widely shared and at least partly enforced, that promote the interests of participating countries, most notably their interest in territorial nonaggression and relatively open economic exchange.

The postwar order may be in more danger than at any time since 1990.

The result is a material set of influences on states. The economic alignment of powerful countries, for example, made it possible for these countries to set standards—in the rule of law, financial and monetary policy, technology interoperability, and many other areas—and then to attract new adherents eager to benefit from the resulting coordination. Countries that sought cutting-edge technology, foreign direct investment, or support from international financial organizations found themselves at least partly constrained by the order’s rules and norms. Exclusion from the economic order has proved economically fatal—ensuring that the vast majority of countries adjust their behavior, at least to a degree, in order to remain tethered to the international system.

The postwar order is often held to be the sum of its institutional parts, but its wider gravitational effect is the real source of its power. The order’s norms and institutions derive from a more essential underlying force—the corresponding interests of a critical mass of the world community and the resulting global influence of that bloc. Dozens of leading economic and military powers have come to view the postwar order as essential to creating the conditions that produce economic and territorial security for themselves. Over time, the states enmeshed in the international order have been joined by potent nonstate actors: nongovernmental organizations, businesses, political parties, and movements now play important roles in advocating for and enforcing the order’s rules. By conditioning full participation in economic, political, and even cultural networks on those rules, the states and nonstate actors at the core of the order create a formidable echo effect on world politics.

In the wake of Russia’s invasion of Ukraine, the full power of this order has been unleashed on Moscow. A core group of leading democracies and nonstate actors have rallied to the system’s defense, using components of the order—from the United Nations to economic institutions and networks to the International Criminal Court—to threaten or impose penalties on those who defy it. These actions demonstrate that the postwar order is much more than just a product of U.S. power: far from blindly agreeing to American demands, these states and nonstate actors have defended the system out of their own volition and in pursuit of their own perceived interests.


If the global reaction to Russia’s aggression has shown the postwar order to be far more than a myth, it has also made clear how vulnerable that order is. A direct assault by revisionist powers is often portrayed as the greatest threat to any international system. As the crisis in Ukraine has revealed, however, the more violently revisionists attack an order, the more powerfully its defenders will fight back. Frontal attacks on existing structures tend to consolidate the perceived interests and values that bind them together—a lesson China has also learned from its aggressive “Wolf Warrior” diplomacy. In addition, obvious rule flouting hurts revisionists’ ability to enlist support for their actions, even from countries with hesitations or grievances about the existing system.

The postwar order is therefore less vulnerable to sledgehammer blows by revisionist powers than it is to two other vulnerabilities revealed by the current crisis, both of which have the potential to erode the consensus around postwar norms and principles. The first is excessive ambition: the architects of the postwar system risk pushing their objectives too far and generating a violent backlash. This is arguably what happened with NATO in Europe. Under the United States’ watch, the alliance metastasized from a measured and carefully calibrated program to fortify European security into a limitless, duty-bound imperative. Without endorsing the legitimacy of Russia’s claim to dominate the countries of its near abroad, it is possible to acknowledge that Moscow was always bound to object to NATO’s expansion into areas it perceives as core security concerns.

Another product of excessive ambition is the concept of liberal interventionism, which helped to justify a series of interventions, from Iraq to Libya, which have done much damage to U.S. credibility. Elaborate ambitions for the postwar order’s rules and norms also produced absolutist nonproliferation goals that led U.S. administrations to abandon imperfect but useful stopgap accords such as the 1994 Agreed Framework with North Korea and the 2015 nuclear deal with Iran. Pushing for absolute and uncompromising enforcement of any order’s rules is not a sustainable approach.

The postwar order might perish not with the bang of a direct revisionist attack but with a whimper, as middle powers gradually drift away from its core institutions.

The second vulnerability of the postwar order is the growing influence of what can be termed the “hedging middle” in world politics—countries that prefer to avoid taking sides in the U.S.-Chinese and U.S.-Russian rivalries and therefore hesitate to enforce the norms of the order. These countries—including Brazil, Egypt, India, Indonesia, Saudi Arabia, South Africa, and Turkey—participate in and support many elements of the international system. They broadly support the order’s norms and typically respect them. Some of these countries are set to become major economic and military players. Yet if more of them come to see a Chinese-Russian axis as a useful counterweight to U.S. and Western dominance and therefore defect from U.S.-led institutions, the postwar order will be in deep trouble.

This dynamic is already apparent in the international response to Russia’s war. While impressive by any historical comparison, the global reaction has been more cautious than many realize. Less than two dozen countries are fully committed to imposing economic sanctions against Moscow, and many in the hedging middle have explicitly rejected such measures. Political leaders, scholars, and pundits in many developing countries have rejected the U.S. and European narrative on Ukraine and questioned the legitimacy of U.S. leadership. These divisions could deepen in the coming weeks if the situation on the ground becomes more ambiguous—for example, if Russia calls for a cease-fire to consolidate its territorial gains and Moscow and Beijing begin rounding up support from hedging countries.

In this way, the postwar order might perish not with the bang of a direct revisionist attack but with a whimper, as middle powers gradually drift away from its core institutions, decline to enforce its norms, and join China and even Russia in various efforts to formulate a more multipolar world system. Such a process would likely play out across dozens of institutions and issue areas, fragmenting and sometimes regionalizing trade, investment, and information flows and much else. And it could be accelerated by the continued rise of angry, resentful, self-glorifying nationalism in many countries.

Such a scenario illustrates how these two vulnerabilities of the international order are intertwined. It is when excessive ambition generates crises—whether over Iran, North Korea, or Ukraine—that the hedgers are backed into the most uncomfortable position. Events demand that they choose a side. In failing to do so, they seem to weaken the norms of the order—even though they had no desire to endorse the rule breakers and even though they broadly support those norms themselves.


This dynamic points to an uncomfortable truth. To preserve the postwar international order, Washington will have to moderate and restrict its promotion of the order’s norms and the enforcement of its rules. A rigid and uncompromising approach will produce repeated overreach, provoke needless backlash from hedging states, and ultimately jeopardize the consensus at the order’s core. This may be the most important lesson of recent events in Europe and beyond: the United States needs to embrace a practical and sustainable, rather than inflexible and absolute, approach to the rules-based order.

Such an approach should focus on a few nonnegotiable norms: constraints on physical and cyber-aggression, collaboration on climate change, and cooperation to promote a stable global trade and financial system. It would accept the need to work with democracies and nondemocracies alike. It would actively promote free societies but do so by helping established and emerging democracies rather than forcing change on undemocratic ones. It would accept flawed but effective arms control deals rather than holding out for perfection.

At a moment when much of the world is aligned against Russian aggression, it may seem counterintuitive to suggest that Washington should dial back the intensity of its defense and promotion of the rules-based order. After all, that order has given the United States a tremendous competitive advantage and helped stabilize world politics. But the war in Ukraine has exposed the system’s brittleness. And unless the United States adopts a more pragmatic and flexible approach to maintaining it, the postwar order may collapse into a new era of conflict.

You are reading a free article.

Subscribe to Foreign Affairs to get unlimited access.

  • Paywall-free reading of new articles and a century of archives
  • Unlock access to iOS/Android apps to save editions for offline reading
  • Six issues a year in print, online, and audio editions
Subscribe Now