One ancient concept is dominating global headlines today and it’s not coming from a think tank or a university press release. It’s coming straight from the mouth of Chinese President Xi Jinping, delivered face-to-face to US President Donald Trump at the Great Hall of the People in Beijing.
“The world has once again reached a new crossroads,” Xi said in his opening remarks, broadcast by Chinese state media CCTV. “Can the US and China transcend the Thucydides Trap and pioneer a new paradigm for major-power relations?”
If you’ve been seeing that phrase everywhere and aren’t sure what it means; here’s everything you need to know.
What Is the Thucydides Trap?
The Thucydides Trap is a concept in international relations that describes the dangerous structural tension that tends to emerge when a rising power threatens to displace an established one. More often than not, history suggests, that tension ends in war.
The term was coined around 2011 by Graham Allison, a Harvard political scientist and director of the Belfer Center for Science and International Affairs. It draws on the ancient Greek historian Thucydides, who documented the Peloponnesian War between Athens and Sparta. His observation was direct: “It was the rise of Athens and the fear that this instilled in Sparta that made war inevitable.”
Allison expanded the concept in his 2017 book, Destined for War: Can America and China Escape Thucydides’s Trap?, examining 16 historical cases where a rising power challenged a ruling one. Twelve of those rivalries ended in armed conflict. Only four avoided war.
The Historical Track Record
The pattern Allison identified is not obscure. Some of the most consequential conflicts of the modern era fit the model:
- World War I — The rise of Germany challenged British and French dominance, setting off a chain reaction that pulled the entire world into conflict.
- World War II (Pacific Theatre) — Japan’s rapid rise as an imperial power in Asia collided with US dominance in the Pacific, culminating in Pearl Harbor.
- Cold War (avoided) — The US and Soviet Union both had the means for total destruction. Nuclear deterrence and carefully managed diplomacy prevented the trap from closing.
These cases matter because they show the pattern is real, but also that it is not inevitable. The Cold War proves that great powers, under sufficient pressure, can choose restraint.
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Why the US-China Rivalry Fits the Framework
The current US-China dynamic mirrors the conditions Thucydides described almost exactly. China’s rise across economic, technological, and military dimensions directly challenges America’s long-standing dominance as the world’s leading superpower.
The rivalry today spans every major domain of national power:
- Trade: Trump’s second-term trade war escalated sharply in early 2025, with tariffs on Chinese goods surging by as much as 145 percentage points following “Liberation Day” announcements. A temporary truce in late 2025 capped levies at 30%, but structural competition persists.
- Technology: Both countries are locked in a high-stakes race over semiconductors, artificial intelligence, and supply chain dominance. US export restrictions on Chinese tech firms have deepened the rift.
- Military: China announced a 2026 defense budget of $281 billion, a 7% increase from the prior year, with a clear pivot toward AI-enabled “intelligentized” warfare.
- Taiwan: Xi explicitly warned Trump that “‘Taiwan independence’ and cross-Strait peace are as irreconcilable as fire and water.” Washington’s policy of strategic ambiguity providing Taiwan with defensive arms while not formally recognizing its independence remains the single most volatile flashpoint in the relationship.
For deeper context on the economic dimension of this rivalry, the Peterson Institute for International Economics has published extensive research on US-China trade conflict and its cascading global effects.
Xi Has Been Using This Term Since 2014
This is not the first time Xi has invoked the Thucydides Trap and that’s significant. He has deployed the phrase since at least 2014, using it strategically to signal that Beijing is aware of the theory, rejects fatalism about conflict, and wants to reframe the conversation around cooperation rather than confrontation.
In today’s summit, Xi framed the challenge as a shared one: “Can we jointly respond to global challenges and bring greater stability to the world? Can we, for the welfare of our peoples and the future of humanity, open a beautiful future for bilateral relations?”
Trump responded warmly, calling Xi a “great leader” and describing the discussions as “a very important one,” predicting that “the relationship between China and the US will be better than ever.”
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But summit rhetoric and structural realities don’t always align.
Is War Actually Inevitable?
No! and even Allison himself doesn’t argue that it is.
What he argues is that the structural pressures created by power transition are real, persistent, and historically dangerous. Without careful, sustained diplomatic effort, the odds tilt toward conflict. With it, outcomes like the Cold War’s peaceful resolution become possible.
Contemporary conditions do introduce variables that earlier historical cases didn’t have:
- Nuclear deterrence creates an existential floor that neither side has an incentive to breach.
- Economic interdependence means a war between the US and China would devastate both economies and much of the global economy with them.
- International institutions like the UN, WTO, and IMF provide channels for managing disputes short of armed conflict.
The Oxford Academic journal The Chinese Journal of International Politics published research in 2025 arguing that a Thucydidean reading of power politics actually supports a more restrained US grand strategy sustained rivalry without open war.
Critics also push back on Allison’s framing. Chinese scholars largely reject the analogy as a Western framework that functions as updated “China Threat Theory.” Lawrence Freedman, writing for the National Defense University’s journal Prism, has argued that China’s primary ambition is regional influence and that its economic trajectory gives it strong incentives for patience over confrontation.
What Happens Next?
The Trump-Xi summit is a three-day state visit running through May 15. Discussions are expected to cover trade, Taiwan, AI governance, Iran, and rare earth supply chains. US business leaders joined Trump’s delegation, signalling the economic weight on the American side.
Whether this summit produces durable agreements or manages optics is the question analysts are watching. History suggests the real test of whether two powers can escape the Thucydides Trap isn’t what leaders say at summits it’s the accumulation of decisions made in the years between them.
For ongoing coverage of US-China relations and great power competition, Foreign Affairs and The Diplomat remain essential reading.
Key Takeaways
- The Thucydides Trap describes the structural tendency toward war when a rising power challenges a ruling one coined by Harvard’s Graham Allison, drawn from ancient Greek historian Thucydides.
- In 16 historical cases Allison studied, 12 ended in war. Four did not.
- Xi Jinping directly invoked the concept in today’s Beijing summit with Trump, framing it as the defining question of the US-China relationship.
- The rivalry spans trade, technology, military power, and Taiwan making it one of the most complex great-power competitions in modern history.
- War is not inevitable, but avoiding it requires sustained diplomatic management exactly what this summit is attempting to provide.
