When the ancient Greek historian Thucydides chronicled the Peloponnesian War, he did not write only about the clash between Athens and Sparta. He documented the fate of the small city-states caught between them in 431BC. Corcyra and Potidaea, neutral territories with no grand strategy of their own, were crushed, annexed, or forced into allegiance as the two great powers dragged the entire Greek world into conflict.
Thucydides famously wrote that it was the rise of Athens and the fear that this instilled in Sparta that made war inevitable. Yet for the smaller states, there was no trap to escape. There was only destruction when great powers fought. This forgotten truth frames the most dangerous bilateral relationship on earth today.
When President Xi Jinping invoked the Thucydides Trap during his May 2026 summit with President Donald Trump in Beijing, he framed it as a question between two great powers asking whether China and the US can rise above the so-called Thucydides Trap and create a new framework for major-power relations. The concept was popularized by Harvard political scientist Graham Allison, who identified sixteen historical cases over the past five hundred years where a rising power challenged an established one, with twelve ending in war. Allison’s framework casts China as the rising Athens and the US as the established Sparta. It centers on whether these two great powers can avoid destroying each other, while leaving less examined what happens to the smaller states caught in between. At the summit, President Xi warned that if mishandled the two countries could clash or even enter into conflict, leading the entire China-US relationship into a highly dangerous scenario. He emphasized that the Taiwan issue is the most critical matter in their bilateral relation, implicitly acknowledging that miscalculation could materialize the very trap he warned against.
The competition between the US and China has grown far beyond trade into something that locks other countries into its orbit. What started as a tariff dispute has become overlapping conflicts across technology, finance, energy, and data governance, each one reinforcing the others and closing off neutral ground. This creates a situation close to a legal Catch-22 where China’s Ministry of Commerce used its blocking statute for the first time in May 2026 against US sanctions and put multinational companies in a position where following Washington’s extraterritorial rules meant breaking Beijing’s laws and following Beijing’s rules meant breaking Washington’s. This is not a byproduct of the competition but is becoming the competition itself.
US bans on advanced semiconductors and AI chips combined with Chinese limits on gallium, germanium, and rare earths along with rival payment systems like China’s Cross-Border Interbank Payment System (CIPS), which provides cross-border payment services to more than 5,000 banking institutions across 190 countries and regions as an alternative to Western banking rails and clashing visions of internet sovereignty have built up into a tightly connected system where doing business globally increasingly means either choosing a side or paying escalating costs for staying neutral, with the heaviest pressure in tech and finance while other domains retain more space for hedging. These costs hit hardest not the US or China but the countries and firms that have no power over either. China-US trade, technology, and regulatory pressures have repeatedly spilled over into third countries, and Southeast Asia has often been caught in the middle. Vietnam has faced US scrutiny over goods assembled with Chinese-linked inputs, Cambodia experienced significant trade diversion during the 2018 US-China trade war, Malaysia came under pressure to tighten controls on semiconductor shipments, and Singapore has had to navigate the compliance burdens created by competing US and Chinese rules.
More broadly, small states across the globe must navigate between two major powers, leaning toward China for economic reasons and toward the US for security reasons. ASEAN has long relied on non-alignment and hedging to preserve, and of course expand, room to maneuver if possible, but intensifying US-China competition is narrowing that room. Some states have turned rivalry into opportunity. Vietnam has attracted manufacturing shifts and foreign investment as companies diversify supply chains away from China. India, Gulf states, and others actively play both sides or carve strategic niches, extracting economic benefits while maintaining security partnerships. Yet these adaptive strategies have limits, and the space for maneuvering narrows as competition intensifies, leaving smaller states with growing pressure, higher compliance costs, and reduced autonomy.
The relationship between China and the US remains the world’s most dangerous bilateral relationship not because President Xi and President Trump might make war on each other but because small countries worldwide will be the first casualties when that war comes or even when competition intensifies. The real Thucydides Trap is not whether America and China can avoid war with each other but whether small states can survive the rivalry even if both of them somehow manage peaceful coexistence. As fence sitting becomes tense and the legal arms race traps countries in impossible dilemmas, more countries face choices that progressively erode the strategic autonomy they have long relied on. Thucydides wrote about the Peloponnesian War with eyes on all participants including the allies of Athens and Sparta who became victims of the trap. The lesson from ancient Greece is very clear that when great powers fight the weak do not survive, and the stories of Corcyra and Potidaea matter just as much as the struggle between Athens and Sparta.
When Athens and Sparta finally went to war, the first thing that died was the freedom of everyone caught between them. The US and China may or may not escape their trap but regional powers, developing nations, and many other small countries already know themselves to be inside it.