Today marks a century since the end of World War I. But for the singular personality of Adolf Hitler, Europe would likely today to be celebrating a full century of freedom from continental war.

World War I was horribly destructive, of course, but people had experienced comparable horrors before — not only at Carthage or in the rampages of Genghis Kahn, but in the heart of Europe. Estimates vary, but the Napoleonic Wars of a century earlier inflicted roughly as many deaths proportionately. According to Frederick the Great, Prussia lost one-ninth of its population in the Seven Years War. Estimates for the losses entailed in the Thirty Years War are similar, and for centuries the belief prevailed that Germany lost 75 percent of its population in that war. Yet such losses and beliefs about losses did not lead to systematic efforts to abandon war. Further, major wars had often devastated economies for decades, whereas France and Germany recovered economically from World War I in 10 years.

World War I was unique in the fact that it was the first in history to have been preceded by a growing and active (but often derided) antiwar movement. It had been around for a decade or two, and the war seems to have served as a catalyst. At its end, people were willing to embrace the movement’s precepts.

Before the war, it was very easy to find serious writers, analysts, and politicians in Europe and the United States exalting war as beautiful, honorable, holy, sublime, heroic, ennobling, natural, virtuous, glorious, cleansing, manly, necessary, and progressive. Peace, in contrast, was found to be debasing, trivial, and rotten, and characterized by crass materialism, artistic decline, repellant effeminacy, rampant selfishness, base immorality, petrifying stagnation, sordid frivolity, degrading cowardice, corrupting boredom, bovine content, and utter emptiness.

After the war, such pronouncements became rare — nearly non-existent. In an area where war had been accepted as a standard and permanent fixture, the idea now gained currency that war there was no longer an inevitable or necessary fact of life and that major efforts should be made to abandon it.

Historians and political scientists have often noted this shift toward war aversion in Europe. Arnold Toynbee points out that World War I marked the end of a “span of five thousand years during which war had been one of mankind’s master institutions.” And Evan Luard observes that “the First World War transformed traditional attitudes toward war. For the first time there was an almost universal sense that the deliberate launching of a war could now no longer be justified.”

It appears that only one man really disagreed with this development, but he proved to be crucial. As military historian John Keegan puts it, “only one European really wanted war: Adolf Hitler.” Another historian concludes: “Hitler willed, desired, lusted after war…In every country the military advisers anticipated defeat, and the economic advisers expected ruin and bankruptcy.” As political scientist Robert Jervis summarizes, few scholars believe that World War II would have occurred in Europe “had Adolf Hitler not been bent on expansion and conquest.”

As this suggests, in order to bring about another continental war it was necessary for Germany to desire to expand into areas that would inspire military resistance from other major countries and to be willing and able to pursue war when these desires were opposed. Only Hitler possessed that desire and war-willingness.

Although the general theme of eastern expansion had been around for quite a while, and while it was still in the air after World War I, Hitler seems to have been important, and probably crucial, for its incorporation not only into effective German foreign policy, but also into Nazi ideology. But his own political tactics suggest the expansionary theme was not significantly popular. In fact, he found it politically wise to mellow and downplay this element of his thinking as he neared and then attained office. Indeed, for political expedience, he stressed his desire for peace in every foreign policy speech in the 1930s. As Hitler put it late in 1938, “Circumstances have forced me to talk almost exclusively of peace for decades.”

Moreover, only Hitler had the qualities and the leadership abilities to pull off such a war. Most of the other top German leaders were toadies or sycophants, and certainly none could remotely arouse the blind adulation and worship Hitler inspired. Unlike their war‑eager pre‑1914 counterparts, who mainly anticipated that the next war would be brief, decisive, and even redemptive, the German generals of the late 1930s, like their counterparts in the west, almost invariably anticipated, and feared, a repetition of World War I. “In 1914,” observes historian Donald Cameron Watt, “a belligerent military urged a reluctant civilian leadership into war,” while in 1938 and 1939 the military leadership “dragged its feet.” The military leaders were among that near‑consensus in Germany that, as Gerhard Weinberg puts it, “could conceive of another world war only as a repetition of the last great conflict.”

Nor was there much enthusiasm for expansion within Nazi party. Hermann Göring, working with members of Hitler’s foreign office, apparently sought to develop a peaceful foreign policy built around a strong position for Germany within Europe — one of indirect domination — while pursuing the acquisition of overseas colonies. And Hitler’s foreign minister, Joachim von Ribbentrop, far from supporting an invasion to the east as the natural destiny of Germany, advocated instead for the formation of an anti‑British alliance with the Soviet Union and, like Göring, the acquisition of overseas colonies.

And there was certainly no drive for war among the German public. As it happens, there is quite a bit of information about German public opinion during the Nazi era. There were, of course, no public opinion polls, but countless confidential and apparently objective reports on opinion and morale were regularly filed by government, police, and justice officials as well as by the security service and by Nazi party agencies. Reports about German public opinion were smuggled out of the country by supporters of the opposition Socialists and compiled by their leaders in exile. An analysis of this mass of material has led Ian Kershaw to conclude that the German population, like that in other areas of Europe, was “overwhelmingly frightened of the prospect of another war” and approached the prospect of “another conflagration” with “unmistakable dread.” Another analyst of German public opinion characterizes it as “dead set” against major war.

In the midst of the Munich crises of 1938, a motorized division was sent off to the Czech frontier at dusk, as hundreds of thousands of Berliners were leaving work. Remembering how Berliners on these same streets had sent their troops off to war in 1914 by showering them with cheers and flowers, American journalist William Shirer was amazed to see that the citizens of 1938 “ducked into the subways, refused to look on, and the handful that did stood at the curb in utter silence unable to find a word of cheer for the flower of their youth going away to the glorious war.” Hitler emerged to review the troops from his balcony, but even this failed to draw a crowd: “Hitler looked grim, then angry, and soon went inside, leaving his troops to parade by unreviewed.” Shirer called it “the most striking demonstration against war I’ve ever seen” and concluded that the German people were “dead set against war.” Hitler reportedly remarked disgustedly, but as it turned out inaccurately, “with these people I cannot make war.”

As Weinberg concludes, Hitler was “the one man able, willing, and even eager to lead Germany and drag the world into war.” And Hitler was well aware of this. As he told his generals in 1939, “essentially all depends on me, on my existence, because of my political talents.”

Clearly, if, against all odds, Europe’s greatest cataclysm came about only because one spectacularly skilled, lucky, and determined man willed it into existence, this has substantial implications. It suggests, for example, that World War II in Europe was not an inevitable continuation of the first — that it was not somehow in the cards. It also suggests that appeasement may unwisely have been given a bad name. In the 1930s, the British and French were becoming aware that the terms of settlement to World War I had foolishly been too harsh on the Germans and were working to mellow them. That policy might well have worked with any German leader except Hitler. And World War II did not naturally grow out of the instability of the 1920s or the depression of the 1930s. Hitler may have been aided by the turmoil, but his existence was necessary (but not, of course, sufficient) for the war to take place. If he, rather than the man next to him, had been gunned down in the Beer Hall Putsch, it certainly seems that World War II in Europe would not have taken place.

Hitlers are very rare, but there are some resonances today in Russia’s Vladimir Putin and China’s Xi Jinping. Both are shrewd, determined, authoritarian, and quite intelligent, and both are fully in charge and have essentially unlimited tenure in office. Moreover, both, like Hitler, are popular for their success in establishing a stable political and economic environment and for their desire for their countries to play a larger role on the world stage and to overcome what they view as past humiliations of the sort Germans obsessed over in the wake of World War I — going back to the Opium War of 1839 in the case of China and to the collapse of the Soviet empire, and then of the Soviet Union, in the case of Russia.

However, each already presides over a vast contiguous empire of the kind that Hitler fought to fabricate, and, unlike Hitler, who envisioned autarky, both oversee trading states and need a stable and essentially congenial international environment to flourish. Most importantly, except for China’s claim to Taiwan, neither seems to harbor Hitler-like dreams of extensive territorial expansion — although their tinkering around the edges may inspire concern. Primarily, however, both seem to want to be treated with respect and deference. To a considerable degree, it seems sensible for other countries, including the United States, to accept, and even service, such vaporous, cosmetic, and substantially meaningless goals.

Since 1945, Europe, once the most warlike of continents, has remained free from major war for the longest period of time in millennia, a condition, notes historian Paul Johnson, for which “there is no precedent in world history.” More generally, World War III has become the greatest nonevent in human history, something Jervis characterizes as “the greatest change in international politics that we have ever seen.”

In all, it seems unlikely that Europe’s second century after its self-induced disaster of 1914-1918 will be interrupted, like the first, by a violent continental interregnum.

John Mueller is a political scientist at Ohio State University and a senior fellow at the Cato Institute.