Historians are skittish about predicting the future, and not only because there are too many variables and possibilities. It is also not always easy to grasp the significance of events when you are in the middle of them. When the Berlin Wall came down in 1989, people grasped at once that a new era had started. But few Europeans foresaw that the assassination of Austrian Archduke Franz Ferdinand in Sarajevo in June 1914 would precipitate a terrifying, continent-spanning war in which more than 16 million people would be killed, and even tech experts did not understand the significance of the iPhone when Apple’s CEO, Steve Jobs, unveiled it in 2007.

Since Donald Trump’s victory in the U.S. presidential election last November, it has been hard not to think of Isaac Asimov’s classic science fiction trilogy, The Foundation, published just at the end of World War II. In it, humanity’s future has been largely tamed by a brilliant mathematician who uses statistical laws to control human behavior and protect against catastrophic events, ensuring what is supposed to be benevolent and stable rule for centuries. But these assumptions are shattered by the appearance of the Mule, a mutant with extraordinary powers and millions of devoted followers, who threatens to overturn the order and bring back unpredictability.

Is Trump the Mule of our times? He, too, likes to see himself as the destroyer of conventions and rules and the breaker of institutions. And he, too, rose to power on the back of a personal mass following, raising the question of whether he has the potential to change the course of events and create a different United States in a different world. The presidential contest went off calmly, much to the relief of many, but if Trump and his supporters mean what they say, Republican control of the presidency and Congress, along with a pliant Supreme Court, will bring major changes to the way the United States is governed—including to the rule of law. The president-elect has threatened to do away with independent government agencies he doesn’t like, turn others into his own fiefdoms, politicize the military, and bypass Congress with term appointments if it refuses to approve his nominations. He has criticized American allies publicly and, worse, to their adversaries. And he sees no value or benefit to the United States in international law, rules, or institutions such as the United Nations, the World Trade Organization, or the World Health Organization, and he denigrates even bedrock U.S. alliances such as NATO.

Asimov was a scientist, but he was dealing with one of the central questions about individuals’ capacity to change the course of history—specifically those who have the power and the drive to shatter an existing order. And he was also raising a related question: Was the old order doomed anyway, and if so, are such individuals merely agents of the external forces that shaped them? The answer may lie somewhere in the middle. It is unlikely that the young Napoleon Bonaparte, from a modest background, would have been able to rise to power without the upheavals of the French Revolution of 1789. Russian President Vladimir Putin might not have been able to seize the levers of power had the nascent political system of post-Soviet Russia been more established. Like Chinese President Xi Jinping, he has built a highly personal rule, reshaping his powerful country around himself and bringing about major shifts in the global order.

As observers try to gauge what the second Trump presidency will mean for the United States and the world, a more important question may be how well American democracy, and the international order, can withstand the stress. In the face of the Great Depression, the democratic systems of the United Kingdom and the United States proved resilient, but those of Germany and Japan collapsed, and the world descended into the worst military conflict of the modern era. In the United States today, the roots of its democracy run deep, and the dispersal of power between the federal government and the states limits what any one administration can do.

But the experience of the past is a reminder that the strength of institutions can be very hard to assess before they are directly challenged. That holds true for the international order, as well. Although today’s order appears to be stronger and more resilient than its 1930s counterpart, in recent years, norms that were long considered inviolable have been flouted. As of now, it is unclear whether Trump will be able to achieve his often stated goal of massive change to usher in a new age or will find himself constrained—by existing laws and........

© Foreign Affairs