The Ancient Greeks once debated whether man could enter the same river twice. Science has tended to vindicate Heraclitus, who intuited that he could not. We now see the cosmos as dynamic, not settled; historical, not eternal. Nineteenth-century science clinched the shift: Charles Lyell’s geology revealed the dynamism of the Earth; Charles Darwin’s biology, the flux of life.
Early in the 20th century, atomic physics dismantled even the solidity of elements; their mutability remade science—and geopolitics. Soon, Big Bang cosmology recast the universe as a historical drama: a story beginning 13.8 billion years ago, a river in unending motion.
But what of Parmenides, Heraclitus’s putative antagonist? Was his preference for the still point of the eternal an expression of naïveté, a yearning for permanence? Did he lack the courage to admit the ephemerality of all existence? Perhaps. But the idea of the unchanging river retains immense power. It resonates in the Brahman, Allah, and God; all represent the infinite, the eternal.
Nor is immutability just a theological premise. It inheres in the premise that human life possesses transcendent value—a proposition rooted in the claim that man is made imago Dei, in the image of God. Like the once-immutable atom, this idea has immense geopolitical consequences. The transcendent value of human life constitutes the normative foundation of liberalism—of any political order committed to natural rights.
Machines in Motion
The conflict between flux and stasis animates all great political challenges, including world order. Like all natural efflorescences, political orders are machines in motion. Their dynamism is not easy to grasp. Just as we describe great rivers—the Amazon, Nile, and Mississippi—as if they possessed stable properties, so too do we describe international orders—the systems made in 1648, 1714, 1814, 1919, 1945—as if they possessed much greater inherent stability, or orderliness, than they in fact sustained.
Consider the 19th century. At its start, the average West European was an illiterate peasant; by its end, she might well be an urban worker, commuting by train. To conceive of the phase 1814–1914 as a stable order casts a shroud of false stability over a century of revolutionary change—change that remade the political order of Europe and the world.
The contemporary world, likewise, has undergone flux that defies the premise of coherent international order. Begin—as realists do—with the balance of power. Efforts to build international institutions during World War II were undertaken by the Western powers—and, for the most part, with Western purposes in mind. Initiated in a historical moment when Europe and the United States still dominated global affairs, new institutions of order like the United Nations took the West’s domination for granted.
But dominance proved fleeting. Beginning with the independence of India in 1947 and Indonesia in 1948, decolonization emancipated the West’s colonies. By the late 1970s, nearly all human beings were citizens of nation-states, which counted, in turn, as members of the states system. The “new nations” acquired real power: By the century’s end, the Asia-Pacific was supplanting the North Atlantic as the locus of global production and power. What Walt Rostow once called “the diffusion of power” remade an international order centered on the West into a more pluralistic and decentralized structure.
The Remaking of Hegemonic Leadership
The diffusion of power has been one decisive vector of change in the postwar era. No less consequential has been the remaking of hegemonic leadership. For a quarter century after 1945, the United States played in world affairs a role akin to what the “big man” does in a segmentary society. Washington cajoled and coerced, calling in favors and distributing gifts to sustain an anti-Communist alliance of nation-states. What made hegemony work was American material abundance. For a quarter century, the output of American factories and farms powered what US historian Charles S. Maier calls an “empire of production.”
By the early 1970s, the postwar model was faltering. The American balance of trade flagged, and the United States struggled to maintain the dollar at the parity fixed in 1944. Over the next half century, America’s relationship to the world economy transformed. Washington still retained singular responsibilities for world-ordering, but the United States ceased to be a self-propelled superpower, reliant upon endogenous production to sustain international order. Like empires past, the Pax Americana came to depend on foreign capital, cheap foreign labor, and a geyser of imports to sustain its balance of payments.
The diffusion of power and the remaking of American hegemony have exposed the limitations of institutions and relationships forged during the 1940s. Sometimes, institutions have adapted. The International Monetary Fund during the 1970s ceased to be an enforcer of exchange rate stability and became an advisor to countries moving toward the market. Other institutions proved less adaptive. The Security Council of the United Nations, for example, has enshrined a kind of affirmative action for erstwhile colonial powers.
Persistent Dangers
Amid historical flux, grave challenges that emerged during the postwar era still persist. These include nuclear weapons, which became in the 1950s and 1960s an ironic source of international order—a terrifying impetus to superpower peace. Even in diminished numbers, these weapons remain a source of grave risk, especially as nuclear capabilities proliferate and the logic of deterrence becomes multilateral, not bilateral. The pursuit of peace in a thermonuclear world remains a dance on the rim of the abyss.
Newer risks compound the challenges for global order today, including risks resulting from material progress. The Cold War may have been a conflict between ideologies of modernity, but it was fought in an agrarian world. Only during the 1980s did the proportion of humanity employed in agriculture drop below 50 percent. The results have included real improvements to the human condition: The average human being today lives to over 73 years, compared to 62 years in 1980. But the wages of progress—the flow of Heraclitus’ river, we might say—are measured in CO2 emissions.
More than half the atmospheric greenhouse gases attributable to human emissions have been produced since 1990, in the era of global industrial development. Unlike the Cold War’s nuclear weapons, the resulting risks do not augur the extinction of our species, but climate catastrophe can kill hundreds of millions in the 21st century. And whereas nuclear Armageddon remains a low-probability, high-impact risk, the adverse effects of the climate crisis are a near certainty. Global order today has no graver nor more urgent challenges, but evidently little institutional aptitude, or capability, for the task.
No Turning Back
So volatile are the challenges of our times that we must beware the temptation to turn the clock back to 1945, to “make international order great again.” Nostalgia in politics is a powerful force, and its allure is manifest in the upsurge of conversation about the “rules-based international order,” the “liberal international order,” and “the world America made.”
In a moment when the institutional and cultural bedrock of world order is appreciably fraying, the familiar seduces. It can easily become a lodestar for policy, as was the case during the recent administration of former US President Joe Biden, which keyed its policy to beliefs about the nature of world order and the scope of American responsibility that the president had imbibed during his decades of service in the nation’s capital.
Rebuilding global order instead requires thinking outside the box—or, more precisely, outside the Beltway. Perhaps the European allies of the United States can provide fresh perspective, although they too must beware the pitfalls of the Cold War paradigm.
After all, European and American leaders have been debating the delegation of authority and responsibility since the Eisenhower administration. A formula for burden-sharing that empowers European decision-makers in return for their assumption of rising defense expenditures will not renew world order for the 21st century; it will be new wine in old flasks. Rather, Americans and their European allies must look beyond the challenges of the postwar era—and decide for themselves what today’s challenges really are.
As they do this, leaders might recall the old debate between Heraclitus and Parmenides. Modernity, we might easily conclude, has vindicated Heraclitus. Irrigated by science, the river of progress is rushing us forward—perhaps toward safe harbor, perhaps toward the abyss. Regardless, we might conclude that leadership lies in aligning technical solutions to the vectors of breakneck change. To renew world order, we must discern the drivers of change in our contemporary world and learn how to disarm, if not master, them.
The Need for Legitimacy
Not so fast. To be legitimate, political orders require not only adaptivity to change but also meaningful orientation toward values and purposes that transcend historical change. Here we might recall Parmenides, whose orientation toward the immutable anticipated not only Plato’s theory of the forms but also much subsequent theology. The Apostle Paul, for example, urged the early Christians of Corinth to fixate “not on what is seen” and “temporary” but on what is “unseen” and “eternal.” In Paul’s foundational theology, the church oriented itself toward eternal truths that transcend historical experience.
Legitimate international orders require such orientation. To be sure, the ulterior purposes that motivate political orders need not be Christian, far less democratic. The Congress of Vienna, as its great historian Paul Schroeder argued, was enacted among conservative elites who sought to contain the emancipatory tumult that the French Revolution had unleashed and to preserve an order that upheld the prerogatives of hereditary elites.
The founders of the post-1945 order enacted more universalist foundations, especially in Europe. Recoiling from the horrors of fascist nihilism, Catholic thinkers like Jacques Maritain strived to situate transcendent principles at the normative heart of postwar order. The Universal Declaration of Human Rights of 1948 and, even more consequentially, the European Convention on Human Rights of 1950 made the eternal dignity of the individual human—imago Dei—the normative basis for world order. However violently this ideal was dishonored in practice, it remained a lodestar to which idealists could return.
Global Order in Our Times
Such ideals might today inspire the renewal of global order in our times, as the example of the late Pope Francis suggests. Our concern for the poor, the marginal, the refugee, Francis argued, is the truest barometer of our political accomplishments. Doing for the least of us remains an impossible standard for political institutions, but transcendent purposes give us orientation, not programmatic manifestos.
Moreover, the transcendent values that we articulate do, on occasion, make a practical difference. Thanks, in part, to the implantation of human rights in its postwar institutions, Europe in the decades since 1945 has transcended its prewar descent into fascist nihilism. A region of the world exemplary for its violence and its tumult became in the postwar era an exemplar of relative peace, even civilization. Europe’s example indicates that adaptiveness to change need not compromise fidelity to the eternal.
Historical change, as the experience of modernity teaches, is inevitable; the river flows onward, as Heraclitus discerned. But the ulterior meaning that motivates political action must not be so mutable. Only by grounding political order—global or otherwise—in some still point of eternal possibility can we hope to steer a course through the flood.
Daniel J. Sargent, starting July 1, is Alexander F. and May T. Morrison Professor of American History and American Citizenship at the University of California, Berkeley.
