So much of what we imagine to be new is old; so many of the seemingly novel illnesses that afflict modern society are really just resurgent cancers, diagnosed and described long ago. Autocrats have risen before; they have used mass violence before; they have broken the laws of war before. In 1950, in the preface she wrote to the first edition of The Origins of Totalitarianism, Hannah Arendt, knowing that what had just passed could repeat itself, described the scant half decade that had elapsed since the end of the Second World War as an era of great unease: “Never has our future been more unpredictable, never have we depended so much on political forces that cannot be trusted to follow the rules of common sense and self-interest—forces that look like sheer insanity, if judged by the standards of other centuries.”

The toxic nationalism and open racism of Nazi Germany, only recently defeated; the Soviet Union’s ongoing, cynical attacks on liberal values and what it called “bourgeois democracy”; the division of the world into warring camps; the large influx of refugees; the rise of new forms of broadcast media capable of pumping out disinformation and propaganda on a mass scale; the emergence of an uninterested, apathetic majority, easily placated with simple bromides and outright lies; and above all the phenomenon of totalitarianism, which she described as an “entirely new form of government”—all of these things led Arendt to believe that a darker era was about to begin.

She was wrong, or partly so. Although much of the world would remain, for the rest of the 20th century, in thrall to violent and aggressive dictatorships, in 1950 North America and Western Europe were in fact just at the beginning of an era of growth and prosperity that would carry them to new heights of wealth and power. The French would remember this era as Les Trente Glorieuses; the Italians would speak of the boom economico, the Germans of the Wirtschaftswunder. In this same era, liberal democracy, a political system that had failed spectacularly in 1930s Europe, finally flourished. So did international integration. The Council of Europe, the North Atlantic Treaty Organization, the eventual European Union—all of these institutions not only supported the liberal democracies but knit them together more tightly than ever before. The result was certainly not a utopia—by the 1970s, growth had slowed; unemployment and inflation soared—but it nevertheless seemed, at least to those who lived inside the secure Western bubble, that the forces of what Arendt had called “sheer insanity” had been kept at bay.

Now we live in a different era, one in which growth at those 1950s levels is impossible to imagine. Inequality has grown exponentially, creating huge divides between a tiny billionaire class and everyone else. International integration is failing; declining birth rates, combined with a wave of immigration from the Middle East and North Africa, have created an angry rise of nostalgia and xenophobia. Worse, some of the elements that made the postwar Western world so prosperous—some of the elements that Arendt’s pessimistic analysis missed—are fading away. The American security guarantee that underlies the stability of Europe and North America is more uncertain than it has ever been. America’s own democracy, which served as a role model for so many others, is challenged as it has not been in decades, including by those who no longer accept the results of American elections. At the same time, the world’s autocracies have now accumulated enough wealth and influence to challenge the liberal democracies, ideologically as well as economically. The leaders of China, Russia, Iran, Belarus, and Cuba often work together, supporting one another, drawing on kleptocratic resources—money, property, business influence—at a level Hitler or Stalin could never have imagined. Russia has defied the entire postwar European order by invading Ukraine.