When Presidents Trump and Xi meet at Mar-a-Lago on Thursday, they will bring a common conviction that the fates of their nations—especially on grand issues like war and peace—rest firmly in their hands. Each has vowed to make his respective country great again (what Xi called “the great rejuvenation of the Chinese nation”). And each believes that the vision and determination of a strong leader with an unyielding agenda shape events; not vice versa.

While it is merely coincidental, it is nonetheless fitting that their summit occurs on the precise centennial of the day another world leader who shared their convictions about leadership got mugged by reality.

After three years of pledging to stay out, the United States entered World War I on April 6, 1917. An ardent opponent of U.S. entanglement in what he called a “European war,” Woodrow Wilson had just five months earlier won reelection to a second term in a campaign  built on his success in keeping America out of war. But the brutal logic of events overseas eventually forced his hand. The lesson for Xi and Trump today as they contend with an increasingly brazen, nuclear-armed North Korea, is best captured in Leon Trotsky’s insight: “You may not be interested in war, but war is interested in you.”

Wilson’s arc from strident non-interventionism to a declaration of war begins with a phrase now laden with historical baggage: “America First.” Long before Trump used it to define his foreign policy, before even Charles Lindbergh made it the banner of his pre-World War II isolationism, Wilson made “America First” (along with the slogan “He kept us out of war”) a centerpiece of his 1916 campaign.

As Wilson saw it, “America First” initially provided the rationale for staying out of a deadly European war—and then, for entering it.

Wilson had consistently maintained a position of neutrality since the war’s outbreak. He did not even mention the spark that ignited World War I—the June 28, 1914 assassination of Archduke Franz Ferdinand—during his Fourth of July address of that year. One day before Austria declared war on Serbia, Wilson said in a press conference, “The United States has never attempted to interfere in European affairs.” And on August 19, two weeks after Germany, France, and Great Britain had entered the war, Wilson declared that “the United States must be … impartial in thought as well as in action.”

As a former professor, president of Princeton, president of the American Political Science Association, and fervent Presbyterian, Wilson felt obliged to explain why “America First” was not just his choice, but the right choice.  His explanation and justification of this position during his reelection campaign deserves careful rereading today. In an April 1915 speech to the Associated Press at New York’s Waldorf Astoria Hotel, Wilson told reporters:

Let us think of America before we think of Europe. … The basis of neutrality, gentlemen, is not indifference; it is not self-interest. The basis of neutrality is sympathy for mankind. … I am interested in neutrality because there is something so much greater to do than fight; there is a distinction waiting for this Nation that no nation has ever yet got. That is the distinction of absolute self-control and self-mastery. Whom do you admire most among your friends? The irritable man? The man out of whom you can get a ‘rise’ without trying? … Don’t you admire and don’t you fear, if you have to contest with him, the self-mastered man who watches you with calm eye and comes in only when you have carried the thing so far that you must be disposed of? That is the man you respect. ... Now, I covet for America this splendid courage of reserve moral force.

Wilson’s coveted self-mastery began to unwind in January 1917, when Germany, faced with a British blockade, announced it would resume unrestricted submarine warfare, including the sinking of American merchant ships. In February, Wilson learned of the Zimmerman Telegram, a secret message from Germany to Mexico offering Arizona, New Mexico, and Texas in return for joining the war effort against America.

Wilson tried in vain to find a way to respond without going to war. On February 3, he severed diplomatic relations with Germany, and on February 26—after the two American ships Housatonic and Lyman M. Law had been sunk—he requested congressional authority for a policy of “armed neutrality.” Americans ships would be armed and ready to defend against German attacks, but America would not become a belligerent in the war. Even as America’s entry looked inexorable, Wilson clung to his belief in neutrality: “I am not now proposing or contemplating war or any steps that need lead to it. ... No course of my choosing or of theirs will lead to war. War can come only by the willful acts and aggressions of others.”

In the ultimate irony, it was the German intention to keep America out of war that spurred the military tactics which became Wilson’s tipping point. As Fred Iklé notes in his book Every War Must End, in December 1916 the German naval staff came to the conclusion that a policy of unrestricted submarine warfare would force Britain to surrender in just five months. After seeing their ally sue for peace, German analysis went, the Americans would be deterred from fighting the war against Germany. The argument prevailed, and on January 8, 1917, the Kaiser approved the policy.

How wrong the Germans were. Proclaiming to a joint session of Congress that armed neutrality had become “worse than ineffectual” since it was “practically certain to draw us into the war without either the rights or the effectiveness of belligerents,” Wilson asked for a declaration of war against Germany on April 2, 1917. After the Senate and House authorized war, America officially entered World War I on April 6. It was in his speech requesting that authorization that Wilson used language familiar to Americans today—a call to make the world “safe for democracy,” to “bring peace and safety to all nations and make the world itself at last free." Wrapped in a high moral justification, this was the beginning of the foreign policy tradition now known as Wilsonianism.

Wilson’s reversal reminds us that the best intentions—and even the strongest convictions—can be overwhelmed by events. It offers a resonant lesson for Trump and Xi. Despite the fundamental disagreements that can only begin to be addressed at Mar-a-Lago, neither Washington nor Beijing wants war between their two great nations – or a military conflict in North Korea that could drag them into war. Yet events are forcing them to reluctantly consider heretofore unthinkable options.

For Trump, a North Korean regime capable of delivering nuclear payloads against the American homeland is completely unacceptable. On its current trajectory of nuclear and missile tests, Pyongyang will be able to do so before the end of Trump’s first term. Thus, as a senior Trump administration official this week said, “the clock has now run out, and all options are on the table.” Translation: The U.S. is prepared to preemptively strike North Korean targets to prevent Kim Jong Un from advancing further with his nuclear weapons program. For Xi, however, a US preemptive strike (no matter how surgical) presents the specter of a second Korean war, and the intolerable prospect of a Korean peninsula united under a US military ally.

As a result, both parties have a vital national interest in finding a way to halt Kim’s nuclear advance. This was Xi’s message in his first interaction with Trump, when he told the president-elect that “cooperation is the only correct choice for China and the United States.” But Trump will remind Xi that their predecessors have been singing that song for the past decade as North Korea has crossed a succession of red lines: testing nuclear weapons, building an arsenal of warheads, testing longer range missiles, and – soon enough – developing the capability to attack the American homeland. At this point, lofty words will not suffice. If they fail to find a way to join in acting decisively to contain this threat, we will all have good reason to fear a rush of events as consequential as those that upended Woodrow Wilson.