Nothing lasts forever. Every international order has an end. The Pax Romana stabilized the Greater Mediterranean before it fell apart. The British world order flourished in the 19th century but crumbled in the wake of two world wars in the 20th century. Today, in an unstable world led by a chaotic America, it’s hard not to wonder if the U.S.-led order is on the verge of disappearing. So writes Hal Brands, a Bloomberg Opinion columnist and distinguished professor at the Johns Hopkins University School of Advanced International Studies.
Since 1945, that order has brought colossal peace, prosperity, and freedom. It can only be described as a crushing success. But the pressure on it—from both its opponents and its creator—is mounting. One way to gauge how serious the risks have become is to consider the different ways in which an order can end.
The brilliant Cambridge historian Brendan Sims suggests that international order typically ends in one of three ways: military defeat or a catastrophic failure of deterrence; economic decline or a divergence between the political and economic principles of the order; or a breakdown in compliance with its founding rules and norms.
The U.S. order has proven remarkably resilient, but the likelihood of its collapse is growing as America simultaneously increases the risks in each of these dimensions. And while recent leaders, including President Donald Trump, have taken important steps to strengthen the order, America’s current policies are increasingly exacerbating these dangers. The international order can disappear by assassination, exhaustion, or suicide. Today, it is difficult to rule out any of these grim endings.
How America assumed the role of leader
Order is about rules and those who create them. International order is based on commonly accepted norms or principles designed to govern global behavior. These rules are created and maintained by powerful actors and institutions. A number of powers have sought to structure the world to their liking. But since World War II, American order has been the world’s biggest and most successful game. The lesson American policymakers learned from that conflict was that only a secure and prosperous system could guarantee America’s own well-being.
So the United States built an order based on relatively free trade; the supremacy of human rights and democratic values; the prevention of great-power aggression and war; and institutionalized cooperation to address common problems. Washington used its unparalleled military and economic power to prop up the destiny of like-minded nations. America, President Harry Truman said, "assumes the responsibility that Almighty God has ordained" for "the well-being of the world for generations to come."
Make no mistake: American interests are the driving force behind this effort. But because America was so powerful and defined those interests so broadly, this project has brought historic benefits to much of the world. In the decades since the war, democracy has gone from threatened to dominant. Trade has flourished and living standards have risen sharply, first in the free world and then globally with the fall of communism. The world, which has endured two all-consuming wars between great powers in quick succession, has avoided anything like it since 1945. The United States has ushered in a global golden age. However, the pressure on the American order has become impossible to ignore.
Revisionist powers—China, Russia, Iran, North Korea—are challenging a system they see as dangerous to their illiberal regimes and repressive to their geopolitical ambitions. The global South has grown disillusioned with Western dominance. The United States itself has seemed contradictory in recent decades about its role as world leader. The threats to its economic and military supremacy have become more serious. Look at almost any U.S. ally and you will find a conviction that American power remains indispensable—and a concern that the post-World War II order is slipping away. So how real is the danger? Let’s look at three ways in which the world order can collapse.
Losing a War
One path to failure is through defeat or devastation in war. Nothing destroys the authority of a hegemonic power like a humiliating defeat on the battlefield. The Athenian Empire collapsed after losing the Great Peloponnesian War. Britain won World War I but never recovered from its aftermath.
For decades, America was the sole superpower. As last month’s attack on Iran’s nuclear program reminded us, the Pentagon still possesses unprecedented power projection capabilities. But anyone who thinks the United States is militarily invincible has missed some facts. The Pentagon faces a complex military arithmetic problem.
A myriad of challenges—from Russia in Europe, Iran and its proxies in the Middle East, and China and North Korea in Asia—are straining U.S. resources. A superpower whose military is designed to fight one war at a time is always at risk in a world of multiple, interconnected threats. But the danger of crushing defeat is most concentrated in the Western Pacific. "The intelligence is very clear," said Air Force Secretary Frank Kendall in 2023. "China is preparing for war, and specifically for war with the United States." The Chinese threat is real "and may be imminent," Defense Secretary Pete Hegseth noted this year.
These are just two of many alarming statements by American officials. Beijing is amassing forces and rehearsing plans for an attack on Taiwan or a reconfiguration of the Western Pacific. It is racing to build a nuclear arsenal that will match and perhaps surpass America's. Meanwhile, Xi Jinping's government is stockpiling food, fuel, and other resources. Xi would certainly prefer to drive America out of the Western Pacific peacefully. But he is preparing for battle. A war between the United States and China would cause catastrophic economic chaos and carry serious risks of nuclear escalation. And if America loses—which is a real possibility—the damage to American order would be enormous.
America’s alliances in the Indo-Pacific could unravel. A shattered American military could struggle to maintain order in other parts of the world. “The trajectory has to change,” warned Admiral Samuel Paparo, the head of U.S. Indo-Pacific Command: America is not responding with the urgency that the threat demands.
Frankly, there are encouraging developments. Israel, with American help, has been devastating Iran and its allies since late 2023. The United States and its NATO allies have used the war in Ukraine to curb Russian influence. Trump can take some credit for getting allies to agree to spend 3.5 percent of GDP on defense and another 1.5 percent on related investments. Over time, these expenditures will strengthen the military position of the democratic world.
But global tensions remain real, trends in Asia are frightening, and the United States still acts as if it could lose World War III. U.S. military spending is less than 3.5 percent of GDP, one of the lowest levels since World War II, and could fall further next year. Ammunition and missile defense stocks are reportedly low and depleted by recent clashes in the Middle East.
With a moribund shipbuilding industry and a sluggish, fragile industrial base, America would struggle to make up for the losses it suffered in the early stages of the war. "You can't AI your way out of a material deficit," Paparo argues. A country that can't replace its losses on the battlefield won't win a war of attrition between great powers. No one, not even Xi Jinping, knows exactly how capable China's inexperienced military is. But as the military balance in the Pacific shifts, the danger of an order-destroying catastrophe grows.
Economic collapse
The international order doesn't have to collapse suddenly. It can also collapse when the leading power can't—or won't—maintain the economic mechanisms that keep the system going. The British order collapsed when two world wars bankrupted the empire. The American order has long been based on two economic pillars. The first is simply the economic and financial means to maintain America’s global power, including funding the military capacity to deter revisionist threats.
The second pillar consists of economic arrangements that underpin strategic commitments: the international economic leadership, trade and investment ties that bind Washington to its allies and give them a shared interest in keeping the world under American leadership. Both pillars are remarkably resilient. Despite all the talk of decline, America’s share of world GDP is about the same as it was in the 1970s. The dollar dominates global trade and finance.
Foreign investors have long been willing to support the dominance of the dollar and finance large U.S. deficits because those arrangements help Washington finance its alliance commitments and military might. And when the economic arrangements that underpin this world order become outdated or unbalanced, they are usually renegotiated—as happened when the United States abandoned the gold standard in 1971 and moved to the floating exchange rate system we know today. But there are three real problems with the economic structure of the order: waste, protectionism, and politicization. All of them are getting worse. First, waste. A quarter of a century ago, the United States ran a budget surplus.
The deficit now knows no bounds. The U.S. public debt is about 100 percent of GDP. It will soon surpass the 119 percent that America reached at the end of World War II. And if the spending and tax levels enshrined in Trump’s “One Big Beautiful Law” become permanent, the debt could exceed 200% of GDP by 2050. As debt and deficits rise, interest payments and borrowing costs will rise, stifling growth and crowding out defense spending.
At some point, continued profligacy could undermine the dollar’s hegemony, weakening America’s global power—its ability to impose sanctions, for example—and exacerbating all its other economic problems. There is no reliable formula for determining exactly where that dangerous threshold lies—where continued fiscal recklessness ultimately makes global leadership unprofitable or otherwise exacts a crushing geopolitical price. But the United States seems determined to find out. Second, protectionism. The United States has never been shy about renegotiating economic relations with its partners: Recall the brutal trade battles with Japan in the 1980s.
But Trump’s extreme penchant for tariffs could have more lasting, destructive consequences. U.S. allies complain that these tariffs make it harder to increase defense spending. The more the United States bickers over trade with its allies, the more it undermines the collective cohesion and resilience needed to defeat a mercantilist China in everything from shipbuilding to artificial intelligence. At a conference I recently attended in Tokyo, the dominant themes were that China threatens Asia’s security and America threatens the region’s prosperity. A relatively open international economy once bound America and its allies. High tariffs and endless trade wars could drive them apart.
Third, politicization. Trump’s campaign against the independence of the Federal Reserve threatens to undermine the apolitical, competent management of the American economy and weaken the Fed’s ability to act as a global stabilizer in times of crisis. Trump’s reckless use of tariffs in political disputes—over immigration, drugs, or the legal woes of his illiberal satellites—is making America an engine for geoeconomic cataclysm. Trump is playing too loosely with the global economy. It’s hard to imagine many countries supporting such a superpower for long.
Trump Breaks All the Rules
No system of international order can thrive when its key rules are consistently violated or ignored. After it became clear at the end of the Cold War that the Soviet Union would no longer impose socialist regimes on Eastern Europe, the regional order it had built there collapsed.
The American order includes fundamental norms, from the freedom of the common good and counter-proliferation to the protection of human rights and prohibitions on the seizure of territory by one’s neighbor. Although America has occasionally indulged in hegemonic hypocrisy, its advocacy of these rules has helped create a relatively civilized, prosperous world.
Today, unfortunately, these rules are flouted by both good and bad people. Freedom of navigation is under attack from the Red Sea, where the Houthis terrorize shipping, to the Western Pacific, where Beijing claims most of the South China Sea, to the Arctic, where Russia claims international waters along the Northern Sea Route. Human rights standards are deteriorating: China’s treatment of the Uyghurs is the kind of industrial-scale abuse that should have long been a relic of the past. The rise of interstate wars and territorial grabs suggests that deterrence against aggression is waning.
Meanwhile, the U.S. administration, ambivalent about democratic norms at home, has taken an ambiguous stance on defending key norms abroad. Trump has strengthened the nonproliferation regime by striking Iran’s nuclear facilities. He has delivered a stronger (if shorter) pushback against the Houthis than President Joe Biden. If Trump finds a way to support Ukraine, he will also continue the precedent Biden set by supporting the prohibition on territorial acquisition by force. Unfortunately, Trump has not only weakened U.S. support for democracy and human rights abroad, but he has also acted in ways that challenge this very vital norm.
The president has mused about seizing the Panama Canal, annexing Canada, and annexing Greenland (a de facto autonomous territory of NATO ally Denmark) against the will of its people. He has said that the United States could use economic pressure or military force to expand its territory. The norm against territorial expansion is so fundamental that its collapse could plunge the world back into the terrible chaos of past eras. If America itself were to violate this principle, it would be complicit in the demise of its own order.
The End of the World as We Know It
President Bill Clinton used to say that many people lost money betting against America. The same is true of the American order. In the early 1960s, none other than Henry Kissinger argued that America and the system it had created were headed for disaster. In the decades since, the end of the American order has been frequently predicted but never occurred. The fact that the order has survived for generations is a testament to its great resilience and the great efforts that America and its allies have made to protect it when it has been threatened. But don’t think that good things will last forever or that the United States is immune to the dangers that have destroyed the old order.
It is never easy to discern where dangers become catastrophes—where the suffering of a threatened order becomes fatal. America will surely regret that moment when it comes. International orders evolve; change is beneficial. But the ultimate end of an order, whether peaceful or violent, is usually an epic historical event. The country best positioned to shape the post-American era is China, which has a diametrically opposed vision of how the world should function.
Whatever replaces an order, run relatively enlightenedly by a relatively enlightened superpower, will almost certainly not be as good for the world—or for America—as the system we have known since 1945. That order could end in a sharp, bloody clash in the Western Pacific. Or in a long crisis caused by increasing waste and protectionism. Or in a sad slide into irrelevance, the result of the steady erosion of rules. Or perhaps, the end of the American order will come someday at the intersection of these three dangerous paths.
History tells us that there are many ways in which orders break down. A worrying marker of the current moment is that America is pursuing all of them at once.