The American Century Is Over. What Comes Next?
Henry Luce's vision of American global supremacy lasted about seventy-five years. Its end is not a failure — but pretending it hasn't ended is.
In February 1941, Henry Luce published "The American Century" in Life magazine — an essay arguing that the United States had an obligation to lead the world, to spread its values and its economic model, to build the institutions that would organize global order on American terms. Luce's essay was published before Pearl Harbor, before the United States had officially entered World War II, and it was already pointing toward the architecture of the post-war international order: Bretton Woods, the UN, NATO, the Marshall Plan, the global military presence that has been the structural fact of American foreign policy ever since.
The American Century was real. Between 1945 and roughly 2000, the United States was genuinely the indispensable nation — the designer and guarantor of an international order whose rules, institutions, and enforcement mechanisms were American-sponsored and American-led. The dollar was the global reserve currency. The US Navy maintained the freedom of the seas. American universities trained the global elite. American popular culture shaped global aesthetics. The American developmental model — liberal democracy, market capitalism, rule of law — was presented as the universal destination, the end of history toward which all societies were moving.
This order is not ending because the United States has become weak. It is ending because the conditions that made it possible — overwhelming US economic and military superiority relative to every other state — have been eroded by precisely the globalization that the American order helped to produce.
The structural change
In 1945, the United States produced approximately 50 percent of global GDP, having emerged from World War II with its industrial capacity intact while its major competitors had been devastated. That share was always going to decline as other countries rebuilt and developed; the question was how fast.
Today, the US share of global GDP (measured in purchasing power parity) is approximately 15 percent. China's share is approximately 19 percent. The bilateral comparison overstates the symmetry — US per capita income remains more than five times China's, and US technological and institutional capacity remains superior in most dimensions — but the aggregate balance of economic power has shifted fundamentally.
Military power has shifted more slowly, but it has shifted. US defense spending accounts for approximately 40 percent of global military spending; the combination of China, Russia, and their aligned states accounts for roughly another 25 percent. More importantly, the distribution of military capacity relevant to specific regional contingencies has shifted significantly: in the Western Pacific, where Chinese military modernization has been most focused, the US military's ability to prevail quickly in a conflict over Taiwan has declined substantially from its position in the 1990s.
This is not a crisis — decline from unipolar dominance to multi-polar competition is a structural outcome of the development of the international system, not a policy failure. But it requires a foreign policy adjustment that the American political system has been deeply reluctant to make.
The adjustment problem
The political economy of American foreign policy has been organized around the assumption of hegemonic leadership for eighty years. The alliance system, the forward military presence, the global dollar system, the export of the democratic development model — all of these are policies calibrated for a world in which American power is sufficient to underwrite them unilaterally.
In a world where American power is no longer sufficient for unilateral underwriting, these policies require either coalition partners who share the costs or a reduction in scope. Neither coalition building (which requires genuine deference to partners' interests) nor scope reduction (which requires acknowledging limits that American political culture finds humiliating) is natural to a political system organized around the assumption of supremacy.
The consequence is a persistent mismatch between American foreign policy ambitions and American foreign policy capacity — a gap that has been closed, over the past twenty years, by borrowing against the future. The national debt has grown substantially; the defense industrial base has been allowed to atrophy; alliances have been managed as assets to be extracted from rather than relationships to be sustained; and the domestic investment in the economic and technological foundations of long-term power has been deferred in favor of present consumption.
Metaculus forecasts a 61 percent probability that the US share of global military spending will decline below 35 percent before 2030, reflecting both continued Chinese military buildup and fiscal constraints on US defense spending. The trajectory of hegemonic decline is gradual; the political adjustment to it has barely begun.
What a post-hegemonic foreign policy looks like
The United States is not the first hegemonic power to manage relative decline, and history offers some instructive precedents. Britain's transition from Victorian supremacy to the managed retreat of the post-World War II period — a transition that took roughly seventy years and involved significant military engagement along the way — provides the closest analogue.
The British experience suggests that the transition is manageable when two conditions are met: the declining hegemon transfers assets and responsibilities to a capable successor or coalition (as Britain did to the United States after World War II), and the declining hegemon's domestic institutions remain functional enough to manage the political strains of adjustment.
Neither condition is clearly met in the current American case. The most capable candidate successor — China — is an ideological rival and a geopolitical competitor whose values are significantly different from those that underwrite the liberal international order. The coalition alternative — a genuine sharing of global leadership among the United States and its democratic allies in Europe and Asia — has been consistently undermined by American unwillingness to genuinely share leadership rather than simply sub-contracting some military capacity.
The domestic institutional condition is the more uncertain one. American political institutions are under significant stress from polarization, from the concentrated interests that distort policy, and from the cultural exhaustion with global leadership that has been expressed in different registers by both the America First right and the progressive left. Whether these institutions can sustain the sustained, complex, coalition-dependent foreign policy that post-hegemonic competition requires is not obvious.
Sophie Laurent is a contributing writer at The Auguro covering European politics and international affairs. She is based in Paris.