The Second World War has long been “Hitler’s war.” In most histories, he’s the central character in its outbreak, conduct, and apocalyptic conclusion: a wild-eyed madman with mesmerizing oratory who set Germany on a suicidal path of vengeance for its First World War defeat. But what if the Second World War wasn’t Hitler’s war at all—at least not the war he sought?

When Hitler invaded Poland on September 1, 1939, he had been informed by his foreign minister Joachim von Ribbentrop that Great Britain would not honor its pledge to guarantee Poland’s sovereignty. Back-channel chatter from London about possible territorial concessions from Poland further reassured the Führer, who assumed that appeaser Neville Chamberlain would once again seek a solution short of war. Hitler was doubly confident, having inked agreements with Italy, Japan, and the Soviet Union. That constellation of revisionist states, he believed, was more than enough to deter British intervention in his war against Poland. He was mistaken. Two days after Hitler invaded Poland, Chamberlain reluctantly followed his pledge. The French government of Édouard Daladier followed suit a few hours later with even greater reluctance. Dumbfounded, the Führer supposedly turned to Ribbentrop and asked “Now what?” The Second World War was on.

* * *

As Sean McMeekin, the Francis Flournoy Professor of European History and Culture at Bard College, argues in his provocative new book, only one world leader was happy with the events that occurred that fateful first week in September: Joseph Stalin. Stalin’s War turns a familiar story on its head, highlighting how Stalin drew the belligerents to each other and helped bring about the bloodiest war in human history. Though the conflict decimated his own country, it ultimately achieved many of his strategic aims, solidifying the Soviet Union’s dominance from Berlin to Beijing.

McMeekin begins with a brief survey of Soviet foreign policy prior to Stalin’s successful rise to power in the late 1920s. Stalin, he suggests, embraced Vladimir Lenin’s theory of “revolutionary defeatism” after the latter’s death in 1924, acknowledging that the success of the Bolshevik Revolution was largely a product of World War I: “[H]ad two chief coalitions of capitalist countries not been engaged in mortal combat during the imperialist war in 1917…it is doubtful whether the Soviet power would have survived.” In the aftermath of failed Communist revolutions across Europe, Stalin understood that another war would likely create the next great opportunity for Communism to expand. This, McMeekin argues, is key to understanding Stalin’s foreign policy: he hoped for, and eventually attempted to bring about, a “Second Imperialist War” into which the  USSR could intervene—but only once the other states involved had exhausted each other. As Stalin wrote in 1924, “If war breaks out…we will have to take action, but we shall be the last to do so. And we shall do so in order to throw the decisive weight on the scales.”

With this view in mind, Stalin set about preparing the  USSR for that next “imperialist war.” He began with extraordinary violence, collectivizing Soviet agriculture. The aim was to take firm control of the  USSR’s agricultural sector and rural regions in order to pave the way for rapid industrialization. And he largely succeeded. Imported machinery, experts, and engineers generated an enormous increase in military production—paid for with the confiscated grain of starving peasants.

* * *

At the same time, Stalin sought to improve the  USSR’s strategic position. In 1934, the Comintern—the Moscow-based organ responsible for coordinating international Communism—switched its strategy for Communist parties outside of the  USSR from “class against class” to “Popular Front.” They commanded Communist parties outside of the Soviet Union to work with other “anti-fascist” parties on the Left or in the center to block fascist parties from attaining or exercising power. This was accompanied by Soviet military pacts with France and Czechoslovakia, supposedly signaling Soviet willingness to defend the status quo in Europe against Adolf Hitler. Of course, Stalin’s enthusiasm for defending the extant borders of Europe was essentially nil. While the  USSR endorsed the Popular Front abroad, Stalin quietly and repeatedly sought partnership with Nazi Germany, even suggesting a fourth partition of Poland to German diplomats. The objective, McMeekin suggests, remained “the weakening of capitalist regimes by any means necessary and the concomitant global expansion of Communism.” If Germany were to go to war, best it be fought in Western Europe, with the  USSR neutral until both sides were spent. The Popular Front and Soviet strategy through 1939 attempted to avoid isolation and direct conflict westward away from the  USSR.

Stalin’s machinations came to a head in the critical summer months of 1939, when he was wooed by the French and British on one hand and Hitler on the other. He was greatly aided by his superb intelligence networks in the U.S. and Great Britain, as well as fellow travelers enthusiastic about the Soviet project but unaware of its realities. Stalin may have been playing poker during the intensive diplomacy of 1939, but—in the words of historian D.C. Watt—he was doing so while knowing the other players’ cards.

The result was the Molotov-Ribbentrop Pact. In partnering with Hitler, Stalin’s intentions remained the same: turn Hitler westward against Britain and France and expand the  USSR as much as possible. Over the next 22 months, the  USSR scooped up territorial gains in Europe and Asia while providing raw materials to fuel Hitler’s war machine against France and Great Britain. But Stalin’s plans backfired. First, Germany defeated France too quickly. Second, Hitler and Stalin fell out over their ill-gotten spoils, failing to reach agreements on the future of the Molotov-Ribbentrop Pact in November 1940 and then quibbling over the status of the Danube Delta in December 1940. Hitler decided upon invasion that month, to be launched in the spring of 1941.

* * *

When war with Germany finally came on June 22, 1941, the longstanding historical claim has been that Stalin was surprised, despite the preponderance of intelligence showing that Hitler was likely to attack. McMeekin examines ex-Soviet spy Viktor Suvorov’s thesis in Icebreaker (1988)—that Stalin was planning to launch his own offensive against Germany, which Hitler essentially preempted. That claim has been rejected by most Western historians. McMeekin concludes that the Soviets were indeed making aggressive military preparations, but reconsiders their purpose. As he points out, Soviet doctrine centered on the idea of responding to a declaration of war with an overwhelming counteroffensive. For McMeekin, the great shock for Stalin was not that Hitler had betrayed him, but that “his soldiers either did not know how to or did not want to fight.” The combination of the  USSR’s rapid and uneven military mobilization—and Stalin’s brutality toward his own people—meant millions of half-trained, demoralized Soviet soldiers surrendered in the opening phases of the war. Fortunately for Stalin, Hitler proved his equal in brutality, alienating people who might have been willing participants in a post-Soviet order. Despite millions of casualties, the Soviet state survived Operation Barbarossa—barely.

Stalin turned to the United States to help survive the German onslaught. McMeekin’s revelations force readers to fundamentally rethink the U.S. partnership with the  USSR. Stalin in many ways engineered the alliance using networks of spies, fellow travelers, and dupes to drive the United States and Japan into conflict, alleviating the risk of a two-front war against the  USSR. Operation Snow was critical to this end; on the explicit orders of Moscow, Soviet agent and senior U.S. Treasury Department official Harry Dexter White drafted a full-scale oil embargo of Japan in the summer of 1941, which became policy after the Japanese occupied French Indochina later that year. The embargo forced the Japanese government to make a decision: either attack the United States—on whom it depended for key raw materials—or abandon its empire. After several months of negotiations (further sabotaged by Soviet agents in the U.S. government) Japan chose the former. While the two states may have come to blows anyway, McMeekin clearly shows Stalin’s influence on the events leading to Pearl Harbor.

* * *

With Japan’s surprise attack and Germany’s declaration of war on the U.S. four days later, the U.S., U.K., and  USSR now found themselves on the same side. Stalin’s War offers a fundamental reassessment of the Allied coalition that won the Second World War and, in particular, the role of Lend-Lease. At the center of that reevaluation is the conclusion that President Franklin D. Roosevelt consistently received bad advice about the  USSR from his ambassador Joseph Davies and other Stalin sympathizers like Sumner Welles. Such figures also organized a “purge” of the State Department’s leading experts on the  USSR, most of whom had been accurately reporting on Stalin and Stalinism. One by one, Russian-speaking experts unenthusiastic about Stalin found themselves reassigned—figures including famous diplomats George Kennan, Loy Henderson, and Charles “Chip” Bohlen. Even the State Department’s Soviet library was dismantled. Soviet intelligence and American sympathizers wanted to destroy institutional knowledge about the  USSR, clearing the way for their supporters to steer Roosevelt into closer coordination with Stalin.

The result, in McMeekin’s view, was foolish generosity. Roosevelt and Churchill provided $11 billion in total aid through Lend-Lease—the equivalent of over $222 billion today—without, in McMeekin’s words, “demanding anything in return.” In reality, the U.S. did present a bill to the  USSR in 1945, but it went mostly unpaid until after the collapse of the Soviet Union. Nor did the aid that fed, armed, and mechanized Stalin’s armies come with significant political costs for Moscow. Stalin’s agents gained full access to American factories and laboratories without any reciprocity. And Stalin himself wasn’t forced to return any of the land he had seized in 1939, nor to honor all of the provisions agreed to at the Yalta or Tehran Conferences. He used American requests for Russian intervention in the Far East as justification for the “communization” of much of East Asia. Perhaps most egregious was that much of the Lend-Lease aid arrived in the summer of 1945, after the war in Europe was clearly won. Though the late-arriving aid didn’t help achieve victory, it did help Stalin assert Soviet domination over conquered peoples. American and British policymakers realized too late that he shared none of their interests for the postwar world. Stalin had his war—and won it.

* * *

A looming question throughout the book is the counterfactual. Was there an alternative to partnering with Stalin against Hitler? That question has rarely been raised in serious scholarship but merits the consideration McMeekin gives it. The historical evidence in Stalin’s War shows how badly senior statesmen, particularly in the U.S., misunderstood Stalin, the Soviet system, and the price of their alliance with the  USSR. McMeekin goes too far in suggesting that Great Britain, France, “Fascist Italy, Franco’s Spain, and Japan” might have been brought into partnership against the  USSR and Nazi Germany—turning the war into an ideological crusade against both monstrous dictators. The prospects for such a coalition were, arguably, zero. But there were clearly other options besides the practically blank check Roosevelt gave Stalin.

Stalin’s War challenges long-held beliefs about the nature of the Second World War. At its core is the claim that Stalin saw an advantage in the renewal of global hostilities, so he helped facilitate them. Readers may disagree with elements of the argument but they will have no choice but to grapple with profound questions raised about the war—particularly regarding its origins and the price paid for victory. By placing Stalin, not Hitler, at the center of it all, McMeekin adds a compelling contribution to the pantheon of World War II history, one that will inspire debate for a long time to come.