“The world has come to another crossroads,” Chinese President Xi Jinping told U.S. President Donald Trump on Thursday, as the two leaders began their summit in Beijing . Then Xi asked: “Can China and the U.S. overcome the so-called ‘Thucydides Trap’ and create a new paradigm of major-country relations?” Xi was referring to the ancient Athenian historian and military commander Thucydides , who wrote The History of the Peloponnesian War , recounting the nearly three-decade conflict between the former Greek poleis (city-states) of Athens and Sparta. In his account, he wrote: “The growth of the power of Athens, and the alarm which this inspired in Lacedaemon [Sparta], made war inevitable.” While debate on the accuracy of translations continues, the core message stuck: this “inevitability” of conflict when a rising power threatens an existing one was later popularized by American political scientist Graham Allison in the early 2010s as “Thucydides Trap.” But in the modern context, China is Athens, challenging the…