What Thucydides Can Teach Us About Today’s Multi-Matrixed World

“The History of the Peloponnesian War teaches that victory in such a war comes at enormous cost to both sides, so much so it can blur the distinction between victor and loser: everyone loses. This is the same lesson the conflicts in Ukraine and Gaza impart.”

The age of American hegemony in place since the end of the Cold War is over. The United States will remain an economic superpower and, if it navigates an incredibly divisive and legally complex election later this year, it can look forward to internal prosperity, but its role as global hegemon is coming to an end. While President Joe Biden asserts that “America n leadership holds the world together,” funding for Ukraine to fight back Russia’s invasion remains blocked in a partisan political system. There is a cumulative tiredness and disillusionment around America’s foreign interventions. A second Donald Trump presidency would rapidly accelerate America’s retreat from the global stage and seriously undermine alliances like the North Atlantic Treaty Organization (NATO), foundations of the post-1945 international system.

A fear that the United States will abandon Ukraine is causing much consternation in European capitals, but also in Taiwan and with all of America’s allies worldwide. We are moving into a new era, in which international norms are fragmenting, and new dynamics of power are forcing violent change. Øystein Tunsjø, at the Norwegian Institute for Defence Studies, argued in 2020 that the world had entered a new United States–China bipolar international system. While China’s domestic stability and prosperity usually takes precedence for Beijing, and there are challenges to both on the horizon, when it comes to foreign policy, Beijing’s priority is managing its superpower rivalry with the United States. Graham Allison of Harvard University’s Kennedy School has suggested that this emerging superpower rivalry will lead to conflict more often than not.

Allison turns to a passage in Greek historian Thucydides’ History of the Peloponnesian War, the fifth century B.C. conflict between Athens and Sparta. Thucydides writes: “The growth of the power of Athens, and the alarm which this inspired in Lacedaemon, made war inevitable.” In his book, Destined for War: Can America and China Escape Thucydides’s Trap?, Allison defines the Thucydides trap (a term he coined in a 2012 article) as a tendency toward war when an emerging power threatens to displace an existing great power as the hegemon. Allison does not argue that war is always inevitable but, rather, that it is a strong and increasing possibility, claiming, “When a rising power threatens to displace a ruling power,” as China arguably threatens to displace the United States, “the resulting structural stress makes a violent clash the rule, not the exception.” Allison is not the only person to warn of a potential conflict. In 2015, Chinese President Xi Jinping cautioned, “We all need to work together to avoid the Thucydides trap.”