As US retreats from global institutions, experts debate what replaces multilateralism

In September 2025, Donald Trump stood in the lobby of United Nations headquarters in New York and watched the escalator beneath his feet grind to a halt. Minutes later, during his address to the assembled heads of state, the teleprompter failed. The former television personality turned to the room with a half-joking observation: the United Nations had given him two things—a broken escalator and a broken teleprompter. The UN later said Trump's own camera operator had accidentally triggered the escalator malfunction, but the moment carried its own weight regardless. It was a small, almost farcical punctuation on something much larger: the visible fracturing of the post-World War II international order that the United States had helped build and, for decades, anchored.

The United Nations was founded in 1945 with a singular purpose—to prevent wars. Over eighty years, its mandate sprawled to encompass global health, development, climate protection, and countless other domains. Its institutions, particularly the Security Council, were designed to balance competing interests among nations and enforce a rules-based system. Today, those same institutions are widely acknowledged to need fundamental overhaul. But the question animating capitals and think tanks worldwide is no longer whether the UN needs reform. It is whether multilateralism itself—the entire architecture of shared governance and collective decision-making that emerged from the ashes of World War II—is ending, and if so, what replaces it.

Experts disagree sharply on the timeline. Finnish President Alexander Stubb, who holds a doctorate in international relations, argues that the world is experiencing a power vacuum from which a new order will crystallize within five years. Others expect a longer, messier transition. Mark Leonard, director of the European Council on Foreign Relations, recently wrote that the old order has genuinely disappeared, but what comes next is not simply a Chinese-led replacement for an American one. Instead, he warned, "the world will be without any order at all, swept by fragmentation, contagion, and strangulation." Teresa Nogueira Pinto, a globalization expert at Lusofona University in Lisbon, is blunt: the multilateral framework connected to the post-war period is finished. She points to the UN's peacekeeping and peacebuilding missions—most of which, she argues, have failed—and to the Security Council, which no longer represents the world of 2026. Reforming it would require adding permanent members like India, Pakistan, Nigeria, and Ethiopia, a political feat she describes as nearly impossible to imagine.

Johannes Thimm, head of the Americas Research Group at Germany's Institute for International and Security Affairs, offers a more measured assessment. He does not believe the era of international law is completely over. Diplomatic conventions, treaties, and the vast infrastructure of state-to-state agreements continue to function, even if they rarely make headlines. But he acknowledges that violations have mounted—wars of aggression in Ukraine and Iran, breaches of humanitarian law in Gaza. More consequential still, he argues, is the systematic withdrawal of the United States from international institutions and agreements. The Trump administration has left the World Health Organization, the Paris climate accord, UNESCO, and the UN Framework Convention on Climate Change. It has intensified pressure on the International Criminal Court. When the world's most powerful state acts this way, Thimm said, it threatens the system itself—a greater threat than when Russia wages war, because it undermines the legitimacy of the rules themselves.

As American influence recedes, other powers are repositioning. Trump frequently invokes the Monroe Doctrine of 1823, which declared the Western Hemisphere an exclusive American sphere. Applied to the present, this suggests a multipolar world where the United States no longer dominates globally but competes as one power among several. For some nations, this shift carries real risk—they stand to lose the protection and economic benefits that came with American primacy. For others, it is an opportunity. The BRICS alliance of Brazil, Russia, India, China, and South Africa has expanded and grown more assertive, positioning itself as a counterweight to Western-dominated financial institutions. African nations, Pinto notes, are recognizing that previous models did not serve their growth, and they are seizing the chance to reposition themselves. Geopolitics, she observes, is no longer history—it has made a comeback.

Security arrangements are fragmenting and reforming. NATO members worry about further American withdrawal or even military action if Trump pursues his claims to Greenland, which Denmark administers. In the Indo-Pacific and Middle East, US allies are questioning whether American security guarantees can be trusted. In early August, Saudi Arabia, Turkey, and Pakistan launched the Mecca Defense Pact, modeled on NATO's mutual defense structure but smaller and more agile. Europe has formed its own coalition to support Ukraine. These smaller, flexible formats are sometimes called "minilateralism"—a departure from the grand, universal institutions of the postwar era toward nimbler, issue-specific alliances.

Beyond security, states are pursuing new economic and political partnerships. Pinto expects regional alliances to gain importance and potentially deliver better results than global mechanisms. The World Trade Organization, which achieved much in the twentieth century, has been dysfunctional for years. Regional approaches—like the African Continental Free Trade Area, ratified by nearly all African states since 2018—may prove more workable, though implementation has been slow. Three factors will likely shape the distribution of power in a multipolar world, Pinto argues: sovereignty, access to resources, and demographics. Young, growing populations in Africa and Asia could make those regions indispensable. India, she suggests, could become a superpower by century's end.

What emerges from this transition remains uncertain. In the near term, however, Thimm fears the consequences of disorder. "The world will become more violent," he said. "There will be more wars. The wars will become more brutal. It will be more difficult to organize cooperation." He expressed particular anxiety about the next pandemic or global financial crisis—crises that demand collective response but may arrive in a world fragmented into competing blocs. And beneath all of this sits the climate crisis, a challenge that can only be solved through sustained international cooperation. Whether a multipolar world can muster that cooperation remains the question no one can yet answer.