The Strong Do What They Can—and Suffer What They Must
Key takeaways
- JONATHAN KIRSHNER is Vincent Q. and Mary Ann Giffuni Professor of Political Science and International Relations at Boston College.
- It seems to many these days that the world is a jungle beholden only to one law.
- That well-known line comes from an important section of the text known as the Melian Dialogue, in which representatives of Athens browbeat emissaries from the island of Melos.
JONATHAN KIRSHNER is Vincent Q. and Mary Ann Giffuni Professor of Political Science and International Relations at Boston College. He is the author of An Unwritten Future: Realism and Uncertainty in World Politics.
What Thucydides Really Thought About Power. It seems to many these days that the world is a jungle beholden only to one law. Since returning to office in 2025, U.S. President Donald Trump has not only made a spectacle of American power—by striking alleged drug smugglers in the Caribbean, kidnapping Venezuelan President Nicolás Maduro, bombing Iran, and even threatening the sovereignty of allies—he has also made a principle out of it. Trump described Maduro’s capture as a vindication of the “iron laws that have always determined global power.” In a similar vein, White House Deputy Chief of Staff Stephen Miller asserted in January that the world is “governed by force” and “governed by power” and that “these are the iron laws of the world since the beginning of time.” Observers heard in these blunt statements echoes of Thucydides, the ancient Athenian aristocrat often considered the first proponent of the cold-blooded doctrine of realism. The Peloponnesian War, his magisterial opus on Athens’ doomed decades-long conflict with Sparta in the fifth century BC, includes the famous line, “The strong do what they can and the weak suffer what they must.”
That well-known line comes from an important section of the text known as the Melian Dialogue, in which representatives of Athens browbeat emissaries from the island of Melos. After the Athenians fail to persuade the Melians to accept unconditional surrender, they kill all the island’s men and enslave its women and children. Thucydides’s Melos passage has long been cited as proof that little governs the world beyond strength and its exercise—and as evidence that the brilliant Athenian general, historian, and philosopher himself believed that. Generations of students of international relations have been assigned these decontextualized snippets from his vast work and instructed that this was indeed Thucydides’s lesson. Today, a cottage industry of commentators now celebrate (or bemoan) what is described as a Thucydidean turn in American foreign policy. In “How Trump Won Davos,” an essay published in January, the historian Niall Ferguson explicitly invoked the Melian Dialogue to tout the triumph of Trump as a realist in the mode of Thucydides and asserted that, at Melos, “the realists won an emphatic victory.”