As a porn star sues President Donald Trump over a deal to keep her quiet about an alleged affair, and his White House is drained of everyone but his family, it’s hard not to think that America is entering into a period of decadence that rivals Imperial Rome in luridness. Even before the Daniels news, some historians and journalists compared Trump to famously degenerate Roman emperors. In an editorial earlier this year, New Yorker editor David Remnick predicted, “Future scholars will sift through Trump’s digital proclamations the way we now read the chroniclers of Nero’s Rome—to understand how an unhinged emperor can make a mockery of republican institutions, undo the collective nervous system of a country, and degrade the whole of public life.” Caligula has been invoked even more often, a comparison that New York Times columnist Paul Krugman called “unfair”—to Caligula.

If Trump is behaving like a Roman emperor, what does that say about the state of the American empire, the informal hegemony that the United States has enjoyed since 1945? Last summer, conservative pundit Bill Kristol suggested that Trump’s America mirrored the fall of the Roman Empire:

The speed with which we're recapitulating the decline and fall of Rome is impressive. What took Rome centuries we're achieving in months. https://t.co/4TVXc4C5Ex — Bill Kristol (@BillKristol) July 2, 2017

He’s not alone. Last December, leftist columnist Ryan Cooper wrote in The Week, “The American empire is crumbling.” University of Wisconsin historian Alfred McCoy declared to The Intercept that Trump has been demolishing “pillars of U.S. global power.... He’s weakened the NATO alliance; he’s weakened our alliances with Asian allies along the Pacific littoral. He’s proposing to cut back on the scientific research which has given the United States—its military industrial complex—a cutting edge, a leading edge in critical new weapons systems since the early years of the Cold War.” (The Intercept is particularly invested in this analogy: Murtaza Hussain offered a similar analysis for the site two months later.)

The reality of imperial decline is hard to dispute, albeit with qualifications. There’s always a danger that short-term trends can be mistaken for historical inevitabilities. Paul Kennedy argued in his 1987 book The Rise and Fall of Great Powers that America was entering a period of long-term relative decline. He was prescient in many ways, predicting China’s rise and the Soviet Union’s decline, but premature in predicting the weakening of America, which enjoyed a quarter-century of unchallenged dominance; the relative decline has only just begun.

The American empire, which more mainstream scholars prefer to describe in softer terms as global hegemony or the liberal international order, has always rested on three pillars: economic strength, military might, and the soft power of cultural dominance.

