Origins of the Concept¶
The term “Thucydides Trap” derives from the ancient Greek historian Thucydides, who chronicled the devastating Peloponnesian War between Athens and Sparta in the fifth century BCE. In his seminal work History of the Peloponnesian War, Thucydides offered what would become one of the most cited observations in international relations theory: “It was the rise of Athens and the fear that this instilled in Sparta that made war inevitable.”
This single sentence encapsulates a structural dynamic that has repeated throughout history. Athens, enriched by trade and energized by democratic innovation, had transformed from a minor city-state into the dominant power of the Delian League. Sparta, the established hegemon of the Greek world and leader of the Peloponnesian League, watched this rise with mounting alarm. The resulting conflict lasted twenty-seven years and left both powers exhausted, ultimately paving the way for Macedonian conquest.
The modern formulation of the “Thucydides Trap” belongs to Harvard political scientist Graham Allison, who popularized the concept through his 2017 book Destined for War: Can America and China Escape Thucydides’s Trap? Allison’s contribution was to systematize Thucydides’ insight into a framework for analyzing great power transitions, particularly the contemporary rivalry between the united-states and china. His work transformed an ancient historical observation into a predictive model with urgent policy implications.
The Historical Pattern¶
Allison’s research, conducted through the Harvard Belfer Center’s Thucydides Trap Project, examined sixteen cases over the past five hundred years in which a rising power challenged an established one. The findings were sobering: twelve of these sixteen cases—seventy-five percent—resulted in war.
The cases span from the late fifteenth century to the twentieth, including Portugal’s challenge to Spain, the Habsburg challenge to France, and the multiple challenges posed by rising Germany to established European powers. The most destructive instance was Germany’s challenge to Britain and the European order in the early twentieth century, which produced both World War I and, after an unstable interwar period, World War II. Together, these conflicts killed approximately eighty million people and reshaped the entire international system.
The statistical regularity is striking enough to demand explanation. Why should structural position—the relative power trajectories of states—correlate so strongly with armed conflict? The answer lies in the psychological and strategic dynamics that power transitions generate.
The Mechanism: Fear, Honor, and Interest¶
Thucydides identified three fundamental drivers of human behavior that explain why power transitions prove so dangerous: fear, honor, and interest. These categories, remarkably durable across millennia, illuminate the trap’s mechanism.
Fear operates most powerfully on the established power. As a rising challenger grows stronger, the hegemon faces a narrowing window in which it retains military advantage. This creates incentives for preventive war—striking while victory remains achievable rather than waiting until the balance tips irrevocably. Sparta’s decision to confront Athens, despite initial reluctance, reflected precisely this logic. The established power fears not just defeat in a future war but the loss of the security, prosperity, and influence that hegemony provides.
Honor—or what modern analysts might term status, prestige, or recognition—affects the rising power most acutely. Having achieved new capabilities, the rising state expects commensurate respect and influence in international affairs. When the established order fails to accommodate these expectations, the rising power perceives disrespect. China’s frequent invocations of its “century of humiliation” and demands for recognition as a great power reflect this dynamic.
Interest encompasses the material stakes—trade routes, resources, markets, strategic territory—over which great powers compete. As a rising power’s economy grows, so do its interests abroad, inevitably overlapping and conflicting with those of the established hegemon.
These three drivers interact with the security-dilemma—the tragic dynamic in which measures taken by one state for its own defense appear threatening to others, provoking countermeasures that leave all parties less secure. When a rising power builds naval capabilities to protect its trade routes, the hegemon perceives a challenge to its command of the commons. When the hegemon reinforces alliances to maintain the existing order, the rising power sees encirclement. Each side’s defensive actions confirm the other’s fears, creating a spiral of mutual hostility.
Application to US-China Relations¶
The Thucydides Trap framework applies to china and the united-states with uncomfortable precision. China’s rise represents the most dramatic shift in relative economic power in modern history. In 1980, China’s GDP was approximately ten percent of America’s; by purchasing power parity, it now exceeds it. China has built the world’s largest navy by number of vessels, developed sophisticated anti-access/area-denial capabilities, and demonstrated ambitions extending from the South China Sea to global infrastructure through the Belt and Road Initiative.
The structural pressures are clear. The United States, having enjoyed unipolar dominance since the Soviet collapse, now faces a peer competitor for the first time in thirty years. American strategists speak openly of the “pacing threat” and have reoriented military planning, alliance structures, and economic policy around competition with China. The 2022 National Security Strategy explicitly frames China as “the only competitor with both the intent to reshape the international order and, increasingly, the economic, diplomatic, military, and technological power to do it.”
China, for its part, perceives American actions—strengthening alliances with Japan, South Korea, and Australia; supporting Taiwan; restricting technology transfers; conducting freedom of navigation operations—as a coordinated strategy of containment. Chinese leaders invoke historical parallels, warning against “Cold War mentality” while pursuing military modernization that American planners find threatening.
The flashpoints are real. Taiwan represents the most dangerous—a status quo that both sides have found manageable but that may not survive indefinitely. The South China Sea, the Korean Peninsula, and potential economic decoupling all present risks of escalation.
Critiques of the Concept¶
The Thucydides Trap framework, for all its intuitive appeal, has attracted substantial criticism from scholars and policymakers.
Selection bias represents the most fundamental methodological objection. Critics argue that Allison selected cases that fit his thesis while ignoring transitions that occurred peacefully. The rise of Japan after World War II, India’s emergence as a major economy, and Brazil’s growing influence occurred without great power war. If the universe of cases is expanded, the war rate drops considerably.
Nuclear weapons may have fundamentally altered the dynamics of great power competition. The sixteen historical cases occurred in a pre-nuclear world where decisive military victory remained conceivable. Today, any direct conflict between the United States and China risks nuclear escalation with catastrophic consequences. This “crystal ball effect”—the certainty of mutual destruction—may render the historical pattern obsolete.
Economic interdependence between the United States and China far exceeds anything in previous power transitions. Supply chains, financial flows, and technological dependencies create mutual vulnerabilities that would make war economically suicidal for both parties. Some scholars argue this interdependence creates peace incentives unknown to Sparta and Athens or Britain and Germany.
Determinism is another critique. By framing the trap as structural, Allison may inadvertently contribute to a self-fulfilling prophecy. If leaders believe war is likely, they may prepare for it in ways that make it more probable. Critics argue for agency—the capacity of skilled diplomacy and wise leadership to overcome structural pressures.
Cases That Avoided War¶
The four cases in Allison’s study that avoided war merit examination. Most instructive is the transition from British to American hegemony in the late nineteenth and early twentieth centuries. Britain, recognizing the inevitability of American ascendance, consciously accommodated the rising power. The settlement of the Venezuela boundary dispute, the Hay-Pauncefote Treaty granting America control over a future Panama Canal, and British neutrality sympathetic to the Union during the Civil War all reflected strategic accommodation.
Several factors enabled this peaceful transition. Shared language, culture, and political values facilitated trust. Geographic separation reduced direct security competition. Britain faced more pressing threats in Europe, making American friendship valuable. And crucially, British leaders chose accommodation over confrontation.
The cold-war, while not involving direct great power war, presents a more ambiguous case. The United States and Soviet Union engaged in intense competition, proxy wars, and nuclear crises that brought the world to the brink of annihilation. Whether this counts as “avoiding the trap” depends on how one weighs four decades of Cold War against the absence of direct conflict.
What Makes This Time Different¶
Several factors distinguish the US-China competition from historical precedents, cutting in different directions.
Nuclear deterrence remains the most powerful argument for optimism. Both nations possess secure second-strike capabilities, ensuring that any direct conflict risks escalation to nuclear war. This shared vulnerability may impose caution that was unavailable to previous great powers.
Globalization has created economic entanglement without historical parallel. American consumers depend on Chinese manufacturing; Chinese growth depends on access to American technology and markets. Decoupling, if pursued, would impose enormous costs on both economies. This mutual dependence may serve as a brake on conflict, though skeptics note that similar arguments were made about European interdependence before 1914.
The information age creates new domains of competition—cyber, space, artificial intelligence—while also enabling rapid communication that might prevent misunderstandings from escalating. However, the same technologies enable disinformation, surveillance, and novel forms of conflict below the threshold of war.
International institutions, however imperfect, provide forums for managing disputes that did not exist in previous transitions. The United Nations, World Trade Organization, and various bilateral mechanisms offer off-ramps that Sparta and Athens lacked.
Ideology plays an ambiguous role. Unlike the Cold War’s clear ideological divide, the US-China competition involves a more complex mixture of systemic differences and shared participation in the global economy. This may reduce the zero-sum character of the rivalry—or may simply obscure underlying incompatibilities.
Policy Implications¶
If the Thucydides Trap framework has merit, it suggests several policy imperatives for managing great power rivalry.
Strategic empathy—understanding how actions appear from the other side’s perspective—becomes essential. American policymakers must recognize that defensive measures appear threatening to Beijing, while Chinese leaders must understand that assertive behavior confirms American fears. Neither side can afford to interpret the other’s actions in the worst possible light.
Guardrails and communication channels help prevent accidents and misunderstandings from escalating. The US-Soviet experience during the Cold War produced numerous mechanisms—hotlines, arms control agreements, rules of engagement—that reduced the risk of inadvertent conflict. Similar infrastructure is urgently needed for US-China relations.
Managed competition in some domains may be combined with cooperation in others. Climate change, pandemic preparedness, and nuclear nonproliferation represent areas where shared interests might sustain dialogue even amid broader rivalry.
Accommodation on some issues—recognizing legitimate Chinese interests in its near abroad while maintaining core commitments—may reduce threat perceptions. This does not mean abandoning allies or values, but rather distinguishing vital from peripheral interests.
Alternative Frameworks¶
The Thucydides Trap is not the only framework for understanding power transitions. Power transition theory, developed by A.F.K. Organski, emphasizes the risk that arises when a rising power approaches parity with the dominant state. Unlike the Thucydides Trap’s focus on the established power’s fear, power transition theory highlights the rising power’s dissatisfaction with the existing order.
Hegemonic stability theory argues that international order depends on a single dominant power to provide public goods—security, stable currency, open trade. Power transitions are dangerous precisely because they threaten the provision of these goods, creating instability regardless of intentions.
realism in its various forms provides the broader theoretical foundation for these frameworks, emphasizing the structural pressures generated by anarchy and the balance-of-power dynamics that constrain state behavior. These perspectives share a focus on material capabilities and relative power, though they differ in their specific mechanisms and predictions.
Conclusion: Can the Trap Be Escaped?¶
The Thucydides Trap is neither iron law nor mere metaphor. It identifies a genuine structural pressure that has repeatedly produced catastrophic conflict while acknowledging that the trap can be escaped through wisdom, restraint, and accommodation.
The US-China case presents both reasons for concern and grounds for hope. The structural pressures are real—relative power is shifting, interests conflict, and mutual suspicion is deepening. The flashpoints are dangerous, particularly Taiwan. And the ideological dimension, while less stark than during the Cold War, adds an element of regime competition.
Yet this transition also occurs in a context of nuclear deterrence, unprecedented economic interdependence, and international institutions that provide alternatives to war. Both nations have rational incentives to avoid conflict that would prove catastrophic for both. The question is whether rationality, communication, and statesmanship can overcome the fear, honor, and interest that have so often driven great powers to war.
History suggests the odds favor conflict. But history is not destiny. The recognition of the trap is itself a resource—a warning that may enable leaders to take the conscious, difficult steps required to escape it. Whether china and the united-states will prove wise enough to do so remains the defining question of twenty-first century geopolitics, with consequences extending far beyond both nations to the entire international order and the billions of people whose fates depend on how the great powers manage their rivalry in the decades ahead.