When the leaders of the world's two largest economies met in Beijing on Thursday, the opening subject was not Taiwan, trade, or the war in the Middle East. It was a conflict that ended more than two millennia ago.
"The world has come to a new crossroads," Chinese President Xi Jinping told Donald Trump as the two began their summit at the Great Hall of the People in the Chinese capital. "Can China and the United States overcome the so-called 'Thucydides Trap' and create a new paradigm of major-country relations?" Xi asked, prompting a surge in searches for the term and questions over whether he was making a threat against Trump and the US.
What is the Thucydides Trap?
The concept was coined by Harvard political scientist Graham Allison in the early 2010s, drawing on the ancient Greek historian Thucydides's account of the Peloponnesian War — the nearly three-decade conflict between Athens and Sparta that began in 431 BC. "It was the rise of Athens and the fear that this instilled in Sparta that made war inevitable," Thucydides wrote.
Allison applied the pattern to modern history, identifying 16 cases over the past 500 years in which a rising power was seen as threatening an established one, of which 12 ended in war. In this framing, China is cast as the rising Athens to America's Sparta. Xi has invoked the concept since at least 2013 to specifically argue that war is not inevitable — provided both sides exercise restraint.
In a 2015 speech in Seattle, he said there was "no such thing" as an inevitability of conflict, but warned that "should major countries time and again make the mistakes of strategic miscalculation, they might create such traps for themselves." Xi is not the only one drawn to the concept. During Trump's first term, national security adviser HR McMaster and defence secretary James Mattis were both known students of Thucydides. Trump's former chief strategist and alt-right pundit Steve Bannon invoked the trap in a 2018 interview to make the case for standing up to Beijing in an apparent opposite of Xi's reading.
Allison's framework has attracted serious academic criticism, ranging from misidentifying historical cases to producing a model that leaves no room for diplomacy or political agency to prevent conflict. One example that was excluded, according to experts, is the peaceful transfer of global leadership from Britain to the US in the 20th century, which suggests war between a rising and ruling power is far from inevitable.
Taiwan warning
Xi's historical reference came directly before a warning on Taiwan, telling Trump that the two countries "could collide or even come into conflict" if the Taiwan issue is mishandled. Chinese Foreign Ministry spokesperson Mao Ning later summarised Xi's position as "'Taiwan independence' and cross-strait peace are as irreconcilable as fire and water." Trump did not address Taiwan during the joint appearance. A White House readout, which did not mention Taiwan, said the two leaders had "a good meeting" centred on economic cooperation.
Xi adopted a warmer register later in the day, saying China's national rejuvenation and the goal of making America great again "can move forward together completely and can increase prosperity for the entire world." Trump responded on Truth Social, reading Xi's Thucydides reference as a comment on American decline — but placing it in the Biden years. "When President Xi very elegantly referred to the United States as perhaps being a declining nation, he was referring to the tremendous damage we suffered during the four years of Sleepy Joe Biden," Trump wrote early on Friday.
For European observers, the Thucydides Trap underscores the strategic dilemma facing EU member states. As the US and China vie for global influence, Europe must navigate between its transatlantic alliance and its economic ties with Beijing. The summit's outcome, including Xi's warning on Taiwan, has direct implications for European security and trade policy. Trump's Beijing Summit Falls Short as China Holds Firm on Trade and Geopolitics highlights the limited progress on key issues, while EU Must Unite or Face Irrelevance, Greens MEP Warns After Trump-Xi Talks reflects the urgency for a coordinated European response.
