Rules and Power
Modern diplomacy often speaks of a “rules-based international order,” as though the stability of the international system rests primarily on law, institutions, and shared norms among states. Yet the phrase obscures a simpler reality.
International rules matter only when nations possessing both the power and the legitimacy to defend them choose to do so.
Agreements establish standards of conduct, but institutions and appeal to process rarely restrains ambitious states. When violations carry no meaningful consequence, rules gradually lose their force. Over time they become expressions of preference rather than boundaries of conduct.
The modern international system is often described as though it operates on a different principle.
In reality it follows the same logic that has governed political order for centuries: the rules that shape relations among nations rest on the presence of states capable of defending them.
This insight is hardly new. Writing in the fifth century BC, Thucydides observed in his History of the Peloponnesian War that relations among states ultimately rest on power rather than abstract justice. As he wrote, “the strong do what they can and the weak suffer what they must.”
His observation was not a celebration of power but a recognition of the structural realities that shape international politics.
The international order that emerged after the Second World War followed that same pattern. It rested on a durable structure of power that endured for several generations.
At the center of that structure stood the United States and a network of allied nations that possessed both the capability and the willingness to uphold it.
The Structure Behind the Order
By 1945 the distribution of power in the international system had shifted dramatically. Much of Europe and Asia lay devastated by war, while the United States emerged with its industry intact, a navy that dominated the world’s oceans, and alliances that soon extended across the Western world.
For several decades no other power possessed comparable economic or military capacity.
This position allowed the United States and its allies to set the basic conditions of the postwar system. The major sea lanes remained open to global commerce. American security guarantees discouraged attempts to revise borders in Europe and Asia.
Economic arrangements tied the reconstruction of Europe and Japan to a wider system of trade and finance.
Strategic rivalry did not disappear.
The Cold War introduced its own dangers and confrontations. Yet the competition between the United States and the Soviet Union unfolded within limits imposed by nuclear deterrence and the broader balance of power.
Despite the crises of that era basic structure of the international system endured.
The logic of such arrangements would have been familiar to earlier statesmen. Cardinal Richelieu, who helped shape the modern European state system during the seventeenth century, argued that the preservation of political order ultimately rests on the ability of states to defend their interests.
Diplomacy without power, in his view, could not sustain a stable system. The survival of the state itself must guide political conduct — a principle later described as raison d’état.
By the late twentieth century the framework created after 1945 had become familiar enough that many observers ceased to notice the conditions that sustained it.
The system appeared to operate on autopilot through rules and institutions alone. The power that supported those rules receded into the background, visible mainly when a crisis forced it briefly into view.
The Post-Cold War Misreading
The end of the Cold War precipitated a powerful misreading of history and a flawed understanding of the conditions shaping the international system.
When the Soviet Union collapsed in 1991, the binary order that had structured global politics for nearly half a century came to an end.
The principal strategic rival of the United States disappeared, leaving the Western alliance at the center of an international system without a comparable competitor.
Moments of such overwhelming advantage are rare in the history of great powers.
When they occur they often produce a sense of strategic freedom and intellectual confidence. In the years after the Cold War, many Western elites interpreted that moment of dominance as evidence that the character of international politics itself had changed.
The disappearance of a rival encouraged the belief that a fundamentally new era had begun.
Ideas that had once been debated cautiously were now expressed with growing certainty. Market economies spread rapidly across regions that had previously been closed to them and liberal democracy appeared ascendant.
For many observers the collapse of the Soviet Union wrongly appeared to confirm what Francis Fukuyama famously described as “the End of History” — the belief that liberal democracy had effectively resolved the ideological conflicts that had shaped the modern world.
A world moving gradually toward a universal political model seemed increasingly plausible. Democratic governance, open markets, and international institutions were expected to expand across the globe.
Yet earlier generations of statesmen would have regarded such confidence with suspicion if not outright contempt.
Prince Klemens von Metternich, the Austrian statesman who helped restore stability to Europe after the Napoleonic Wars, believed that durable international order rests not on universal ideals but on equilibrium among the major powers. “International politics,” he observed, “is not a matter of principles but of equilibrium.”
The assumptions that took hold after the Cold War moved in the opposite direction.
The spread of democratic institutions was increasingly treated as both a moral objective and a strategic solution.
If democratic states were less likely to fight one another, then encouraging their expansion appeared to offer a path toward a more stable international order.
Yet the early 1990s also presented a more difficult question that received far less sustained attention: how the collapse of the Soviet system might be incorporated into a durable European security settlement.
For a brief period Russia itself was undergoing a profound political and economic transformation.
The Soviet state had disintegrated, its ideological framework abandoned, and its empire dissolved.
The possibility existed—however uncertain—of building a new relationship between Russia and the Western alliance that might gradually integrate the former adversary into a broader security architecture.
That opportunity proved fleeting.
The institutions and habits formed during the Cold War remained largely intact.
NATO, originally created as a defensive alliance against Soviet power, redefined its mission while continuing to expand eastward even after the Soviet state had ceased to exist.
In Moscow this development increasingly came to be viewed as strategic encirclement rather than post-Cold War cooperation.
At the same time, many Western policymakers interpreted the absence of a rival as further evidence that the underlying structure of world events had permanently changed
American power appeared so overwhelming that the rules of the system seemed capable of sustaining themselves.
But the stability of that period did not arise because power had disappeared from international politics. It arose because one power had become so dominant that few were capable of challenging it.
For a time that dominance required little display.
The system functioned smoothly enough that its underlying foundation faded from view, and the rules of the order appeared to operate on their own.
The order of the post-Cold War world rested on the same principle that has governed every international system before it: rules endure only when power exists to uphold them.
What had changed was not the nature of international politics, but the balance within it.
The Return of Strategic Competition
The assumptions that took hold after the Cold War are now encountering the realities they once claimed to displace. Developments in several regions of the world illustrate the change.
The war in Ukraine has returned large-scale interstate conflict to Europe.
China has undertaken a sustained military expansion while militarizing disputed islands in the South China Sea and increasing pressure on Taiwan.
Iran continues to develop ballistic missile capabilities while expanding the reach of proxy forces across the Middle East and moving steadily toward the threshold of nuclear weapons capability.
These developments differ in their origins and regional context., but they share a common feature: each represents a test of the limits of the existing order.
Such tests are a recurring feature of international politics.
When the balance of power shifts, states probe the boundaries that once constrained them.
The limits of the system remain in place, but their authority depends on whether the nations capable of defending them still possess both the will and the capacity to do so.
This relationship between political objectives and force projection capabilities was described clearly by Carl von Clausewitz in the nineteenth century. “War,” he wrote, “is the continuation of politics by other means.”
His observation was not simply about armed conflict but about the enduring relationship between political aims and the power required to secure them.
The forces now reasserting themselves in international politics are not new.
They are the same forces that have shaped relations among states for centuries: rivalry, ambition, and the search for advantage in an uncertain world.
Otto von Bismarck, the architect of German unification and one of the most skilled diplomats of the nineteenth century, expressed a similar insight when he observed that “politics is the art of the possible.”
Durable international arrangements, in his view, depended on the careful management of power among competing states rather than on abstract theory.
Strains Within the Order
The pressures on the post–Cold War order do not come only from outside the Western system. They are increasingly visible within it.
For several decades the alliance structure built during the Cold War rested not only on shared security interests but also on a broad convergence of political assumptions among the nations that sustained it.
That convergence is now under strain.
One example can be seen in growing transatlantic disagreements over the meaning of free expression and the regulation of public discourse.
The United States continues to treat freedom of speech as a near-absolute constitutional principle, while many European governments have adopted increasingly expansive laws regulating online content, political speech, and digital platforms.
These differences reflect deeper divergences about the balance between liberty, order, and state authority.
Strategic disagreements over security commitments, Middle Eastern policy, and economic regulation reveal a Western coalition that is no longer as unified in outlook as it once appeared.
None of these differences mean the alliance system has collapsed. But they do suggest that the political foundations that once supported the order are becoming less certain. They also invite a more serious reconsideration of how well the system still serves the purposes for which it was created.
International order has never rested on rules or institutions alone.
Rules can shape expectations and guide conduct, but they do not defend themselves. Their authority ultimately depends on the power and legitimacy of the states willing to uphold them.
For several decades the extraordinary concentration of power that followed the Cold War allowed the existing order to function with relatively little strain.
That period encouraged the belief that international politics had entered a fundamentally different phase, one in which rules and institutions might gradually replace the older dynamics of rivalry and power.
Recent events suggest otherwise. Strategic competition has returned to the center of international politics, and the assumptions that guided the post-Cold War era are increasingly being tested by both external rivals and internal disagreements within the Western alliance itself.
As the American strategist George Kennan once observed, “power is the decisive factor in international politics.”
The language of rules remains a prominent feature of diplomacy, but the stability of the international system will continue to depend on the ability of states to defend the order they claim to support.
International politics has not changed its character.
What is changing is the structure of power within the system—and with it the illusion that rules alone can sustain expectations unsupported by history.