In mid-April 1945 American GIs entered Buchenwald while their British compatriots marched, horrified, into Bergen-Belsen. There they found scenes of unimaginable suffering, men of bones and skin standing, somehow, on spindly legs, amid piles of emaciated corpses. In those dark days at Buchenwald, Gen. Dwight Eisenhower postponed the burial of the dead so that journalists could be brought to the scene to tell the world what the fight had been about. Even as thousands of typhus-stricken survivors died, witnesses to a liberation that came too late for them, Edward R. Murrow filed reports and Margaret Bourke-White made chilling photographs that documented what must have seemed the nether pole of human depravity, the worst an inhuman regime could achieve. A picture of evil was set; yet that picture, it has long been clear, was distorted and mistaken.

A little over a year ago, as he put the finishing touches on his important new work of history, Bloodlands, Timothy Snyder published a much remarked-upon piece in The New York Review of Books titled—somewhat portentously—"The Holocaust: The Ignored Reality." As in the finished volume, Snyder offered a powerful reminder that the true killing fields of the Holocaust were in German-occupied territories in the east, where first with mass shootings and then at killing centers like the hellish Treblinka the Jews were put to death as Jews—most of them immediately, without staying the night. "The fate of the concentration camp inmates, horrible though it was, is distinct from that of those many millions who were gassed, shot, or starved," Snyder writes in his book. "American and British forces," he continues, "saw none of the major killing sites."

But everybody, more or less, knew that much. A half-century ago Raul Hilberg published the first edition of his classic The Destruction of the European Jews, in which he found fault with "the constant emphasis" in the popular and scholarly perception of the war on "’concentration camps,’ often including the epitomization of Dachau and Buchenwald but rarely embracing any mention of Auschwitz, let alone the faraway camps of Treblinka and Sobibór or Belzec." He was crying in the wilderness, but a few years later a potboiler with the title Treblinka sold hundreds of thousands of copies in Western Europe and the United States, finally putting that dastardly name into wide circulation. Still, perhaps Hilberg’s distinction needs to be reasserted, and Snyder—a walking encyclopedia of arresting facts and conclusive figures—has done so better than anyone.

In his article Snyder further claimed that Auschwitz, a concentration and labor facility that incorporated a death camp, Birkenau, is now so well-known because it allowed survival, both of non-Jews and Jews, perhaps 100,000 people (by comparison, fewer than 100 survived Treblinka, a "pure" death facility). True, but Auschwitz is also renowned as a site of Jew-killing, not simply for the Arbeit macht frei that made it far preferable to Treblinka’s horrors, on average. Thanks to the decades of research and memorialization that have made the Holocaust so familiar, and Auschwitz iconic, it is now the concentration camps, not the extermination camps, that are "ignored." If you ask anybody in the street what happened at the concentration camps, they will tell you—wrongly—that the Nazis put the Jews to death in them. Whereas Buchenwald once left Treblinka in the shadows, the reverse is now closer to the truth.

It turns out, then, that much of what Snyder calls "the ignored reality" of the Holocaust is tolerably well-known; by appealing to it to justify his new project, he is really gathering momentum for a rather different and essentially separate historical undertaking. His goal is to connect the true geography, and the detailed unfolding, of the Holocaust to a wide variety of other crimes, perpetrated both by the Nazis and the Soviet Union, in what he dubs a "history of political mass murder." Though it took many years for the Holocaust even to be named as a separate event, it has also been decades since historians began to call for "historicizing" it, by which they meant finding the proper framework for explaining it, so that it is no longer a mysterious black box into which explanation cannot intrude. In Bloodlands Snyder locates the Holocaust alongside other atrocities in an all-embracing single scheme. And unlike his claim that the Holocaust’s grim reality is poorly known, his attempt to link it to a syndrome of political killing endorsed by Adolf Hitler and Joseph Stalin is new and compelling, at least in many of its specifics.

* * *

Snyder is perhaps the most talented younger historian of modern Europe working today. Astonishingly prolific, he grounds his work in authoritative mastery of the facts, mining tomes of information in multiple languages and brilliantly synthesizing his findings. At the very least, Bloodlands is valuable for its astounding narrative integration of a gruesome era of European history. Following in the footsteps of his mentors, Timothy Garton Ash and Tony Judt, Snyder adopts an anti-totalitarian perspective. (In the depths of his terminal illness, Judt, thanks to Snyder’s selfless assistance, completed what will be his posthumous intellectual history of Europe in the twentieth century.) The upshot of this perspective is that Snyder generally avoids high-flown theoretical propositions in order to give individuals their due, even if just to record their agony and demise. A preternaturally gifted prose stylist, he strives for a moral urgency appropriate to his depressing topics, and he rarely succumbs to bathos.

The narrative of Snyder’s book does offer an argument: political atrocity in the era had a highly specific geography, the "bloodlands" of its title, which stretched from central Poland to western Russia, including Ukraine and the Baltic regions. There, Snyder calculates, 14 million people—not including the fighting soldiers who trampled the same ground—lost their lives in an extended paroxysm of state-organized violence. If you were a victim, it was most likely because you were living in the wrong place, not just at the wrong time.

By choosing a geographical approach to how death undid so many "between Hitler and Stalin," Snyder courts two contending risks. One is that he is simply spelling out on the ground the familiar thesis that totalitarian regimes and despots are uniquely evil. Is it any surprise that in the zone where such titans clashed, and the most massive war in human history took place, there was a lot of civilian carnage? A second risk is that a geographical focus could dislodge the wide variety of explanations historians have offered to put the Holocaust in some sort of context, ones focusing, for example, on the circumstances of the war, notably its economics, and food policy behind the lines, or on the imperial aspirations of the contenders in a common space. Snyder avoids the second risk by integrating many of the existing arguments into his own.

The litany of death begins with three bloodcurdling chapters on Soviet policy in the 1930s. As Snyder usefully points out, Stalin killed civilians in peacetime and within his empire, whereas Hitler by and large waited until the war to conduct his malfeasance, and did so on the periphery of newly conquered territory. Recently another historian, Norman Naimark, discussed under the heading Stalin’s Genocides the bloody episodes of Stalin’s peacetime reign, especially the policy-driven Ukrainian famine of 1933 and the campaigns against kulaks (landowning peasant farmers) and other political enemies that culminated in the so-called Great Terror a few years later. But as Snyder points out, "historians who discuss genocide find themselves answering the question as to whether a given event qualifies, and so classifying rather than explaining." Snyder, by contrast, is right to want an explanation, and he is at pains to demonstrate that the sickening death toll depended first of all on geography.

His approach works particularly well for the Ukrainian famine, especially since Hitler’s expansionist racial utopia would come to rely on Ukraine as its "bread basket." Snyder also emphasizes the "national terror" Stalin visited on Eastern European elites; after all, targeting Polish elites—in Soviet Belarus and Ukraine before Poland itself was gobbled up—was a project to be joined with gusto by Hitler in due time. Snyder’s attitude toward the Gulag is much the same as toward Auschwitz: it is too well-known. The Gulag was tough to endure, although when the civilian death toll mounted obscenely in the Soviet Union it was not in its camps but in collectivization zones and during campaigns of political terror that disproportionately targeted Eastern Europeans (and Poles especially). As Snyder notes disquietingly, "it was Stalin’s Soviet Union that undertook the first shooting campaigns of internal national enemies."

Originally a Poland specialist, Snyder has made a valuable contribution with his identification of what he calls "Molotov-Ribbentrop Europe." He has in mind the era between the dismemberment of Poland by Germany and the Soviet Union in 1939 and the Nazi invasion of its erstwhile ally in 1941, and has named it appropriately enough after the gash torn down the center of Poland by the Nazi and Soviet foreign ministers in order to divide the spoils. Polish suffering, most notoriously with the massacre of the Polish officer corps at Katyn but also on the Nazi side of the line, was a common project, Snyder shows. The line also had considerable relevance later, not least because, though the Germans broke the Molotov-Ribbentrop Pact with Operation Barbarossa, on one side Jews were to be asphyxiated in camps while on the other they were to be gunned down en masse. Only the Jews of Galicia, with their territory reassigned by the Nazis for administrative reasons from one side of the original line to the other, suffered both fates.

But there is a sticking point. For all the commonalities rooted in geography, and sometimes ideology, between the Nazi and Soviet killing campaigns, the Soviet Union did not perpetrate the Holocaust. Snyder, however, contends that the larger framework of political atrocity in the bloodlands still matters for grasping the Jewish fate, and he bolsters the case by making a series of microscopic arguments as he turns his attention to Operation Barbarossa and beyond.

Snyder attributes Barbarossa to contending imperialisms: whereas the Soviet Union had established its economic realm, Hitler could not do the same without trespassing beyond his share of Polish territory. And in the expanding domains cleared by the Wehrmacht (and the trailing Einsatzgruppen executing Jews as partisans), German plans called for copying the macabre Stalinist food policies that had led to ruin before. According to the Hunger Plan of May 1941, there really was a choice between who would get to eat: the German Volk at home or the occupants of newly conquered territory. The latter would have to die by starvation. This did not happen, certainly not comprehensively: an occupation in the midst of war is no easy thing to run according to schemes on paper. But hunger killed millions, most pitilessly in the case of the Soviet POWs, more than 2 million of whom starved to death (the Nazis simply shot half a million more).

When it comes to the Holocaust proper, Snyder’s best insight is that zones occupied by the Germans after the Wehrmacht’s invasion of the Soviet Union were not a blank slate but were often double scenes of crime, with one deadly occupation and security apparatus giving way to another and with the Jews suffering most. In a fascinating passage, Snyder emphasizes less the murderous collaboration of Poles and Ukrainians in Nazi projects than their victimhood under Hitler and Stalin—or rather, explains the one as a result of the other.

Snyder’s point is not only that the Nazis claimed that prior Soviet misrule justified brutal corrective measures. In addition, the Nazis cemented local hatred of the Jews by scapegoating them for communism and the violence it had brought to the area. The Germans could appeal to the prior occupation to confirm "the Nazi worldview," as Snyder puts it, in which the Soviet Union was a "Judeo-Bolshevik" regime. "This psychic nazification," Snyder supposes, "would have been much more difficult without the palpable evidence of Soviet atrocities." The pogroms against Jews, after all, "took place where the Soviets had recently arrived and where Soviet power was recently installed, where for the previous months Soviet organs of coercion had organized arrests, executions and deportations. They were a joint production, a Nazi edition of a Soviet text." It is a counterfactual guess, though a plausible one given the scope of the violence. Of course, collaboration happened in zones where no prior occupation had occurred, just as Jews who had never lived under Soviet rule died—in Auschwitz, chiefly. But Snyder is clearly onto something very important.

Snyder is especially interested in Belarus, whose special circumstances he treats as a showcase for his argument, in which geography mattered even more than in the geographically determined bloodlands as a whole. The Belarussian capital of Minsk and its environs, rife with Soviet partisans (many of them Jewish) after the German advance, was the site of the most significant overlap of Nazi and Soviet ideology and activity at the same time. Millions died. Consecutive occupation thus serves to explain both collaboration and resistance.

No matter how convincing, Snyder’s reoccupation thesis can be only one piece of a general theory of the bloodlands. Snyder never equates Nazi and Soviet brutality or ideology. His chapter on the death camps is a minor masterpiece of synthesis, though his argument about the supreme relevance of successive occupations necessarily wanes in it: the death camps, including the hell of Treblinka, on which Snyder dwells with especially moving care, were nearly all situated in the lands of the so-called General Government, the new colony comprising Polish zones the Soviets had never seen.

In his portrait of the region, Snyder is keen to emphasize widespread suffering, including interethnic cooperation among Jewish and non-Jewish victims of Nazi rule. Correspondingly, he downplays—albeit in the most thought-provoking way—the indigenous Jew-hatred and local reasons for collaboration that historian Jan Gross has heroically brought to light. "Poles would yell at the trains going by," Snyder pauses to note. "The gesture of a finger across the throat, remembered with loathing by a few Jewish survivors, was meant to communicate to the Jews that they were going to die—though not necessarily that the Poles wished this upon them." I am not sure how comforting this last proviso is—or how true. Ascribing so much significance to the wartime clash of external totalitarian regimes in causing hatred and collaboration slights the earlier sources of regional anti-Semitism, notably during the crisis of 1918–19, when the Judeo-Bolshevik myth took root across the area. Snyder says that "almost none" of the collaborators in Jew-killing helped the Nazis "for ideological reasons." But if earlier and continuing anti-Semitism isn’t an ideology, what is?

Snyder underlines the significance of reoccupation and interethnic ties again when he turns to the terrible depredations and the consecutive bouts of resistance in Warsaw, where ghettoized Jews revolted in 1943 against German oppression and Poles (including many Jews) followed suit in 1944. The difference in Snyder’s account of the Polish Home Army, which first helped the Jews and then rose up itself, is that this time it is not simply the past Soviet occupation but a prospective one that explains outcomes.

The destruction of Warsaw set the stage, there and elsewhere, for a Soviet conquest as the Nazi regime crumbled, one in which many German civilians were to meet their end in disorganized headlong flight. When the Soviets drove the Nazis back across the bloodlands, Snyder points out, they most frequently ushered in a re-reoccupation. Lands the Soviets had first taken, and had subsequently lost to the Wehrmacht, were theirs again, but to many civilians the apparent opposition was a single experience of victimhood by tag team. Of course, death, which Stalin’s victory largely stopped in the very areas he had terrorized before Hitler came, is not the only indignity civilians can suffer. Germans, especially German women, became targets as the Soviets raped without compunction.

In the years of ethnic reordering that was only beginning as the war ended, Germans and others were forcibly relocated. Yet rather than make the ending of the Holocaust the justification for a Soviet new order—even though Stalin’s troops had discovered all of its sites, and Soviet journalists like Vasily Grossman had done the most to publicize them—Stalin and his Eastern European allies continued the Jew-hatred. It was not comparable to Hitler’s, Snyder acknowledges, though the threat of new mass purges was ever-present. The central truth is that while Hitler started the Holocaust, Stalin ended it. But Soviet anti-Semitism at the level of ideology and policy did make the true history of the bloodlands impossible to perceive later. "No Soviet account of the war," Snyder writes, "could note one of its central facts: German and Soviet occupation together was worse than German occupation alone."

* * *

Snyder writes in opposition to those who chalk up the era’s violence toward civilians to the pathologies of modernity in a very "abstract way." In The Origins of Totalitarianism, Hannah Arendt extrapolated her depiction of the Holocaust from accounts of concentration camps, and Snyder is right to indict her depiction of the totalitarian campaign against the "superfluous man" as quite simply mistaken. His essential contention is that a microscopic view is more productive than a macroscopic one, and if abutting and overlapping totalitarianisms is what occurred, then it was in a very specific region. Put bluntly, better to be a historian of Eastern Europe than a philosopher if you want to understand this evil.

Yet Snyder’s account presupposes or implies the macroscopic and perhaps even the philosophical. Beyond the comparison of imperialism and occupation—itself necessarily broad, and, anyway, revealing dissimilarities as often as commonalities—Snyder’s accumulation of facts may not permit any broad new explanation of political murder. "Hitler and Stalin rose to power in Berlin and Moscow, but their visions of transformation concerned above all the land between," Snyder notes. True enough, but if Hitler and Stalin remain the prime movers, then explaining what happened in these bloody colonies still ultimately leads back to the totalitarian metropole. In the end Snyder is a historian of totalitarianism who skirts offering a theory of it.

Even within the bloodlands, the variety of ways of explaining death stands out as the main conclusion of Snyder’s project. In an unusual "abstract" he has appended to his narrative, Snyder permits himself to use the sort of big words that are absent in the text and on which explanation often depends. Sometimes, he says, the area was the scene of common projects by superficially opposed parties, like the "de-Enlightenment" visited on Poland after 1939 and the "belligerent complicity" that followed, in which many civilians died as armies clashed for what they thought were alternative ideological visions. Other times, however, the forms of death in the bloodlands were strictly different. The Soviets in the ’30s sought the internal colonial "modernization" of Ukraine and elsewhere, in which kulaks were so many eggs necessary for the omelet. The Nazis in the ’40s, by contrast, wanted a "colonial demodernization" that would lead to an agrarian paradise. The Soviets starved the countryside for the sake of the towns, whereas the Nazis aimed to destroy the urban resistance to realize a peasant utopia. Ultimately, Jews died as part of that latter vision. But then, at the level of explanation, there is no clear answer to what united the bloodlands except that they encompassed a region where totalitarians clashed and people died. Snyder is right to refer to the bloodlands in the plural.

When he turns to his conclusion, Snyder comes near to conceding that his study is therefore preliminary, and more corrective than it is constructive. It lays the foundation for some grand new explanation rather than providing one itself. Snyder is particularly hard-hitting about widespread accounts that attempt to extrapolate from the concentration camps of the west or even of Auschwitz in the east the inner logic of the Nazi regime or of totalitarianism as a whole. More generally, Snyder’s book is an unanswerable criticism of a common intellectual syndrome in which a desire for majestic explanation proceeds without regard for the fine-grained details of what transpired. "For the time being," Snyder warns, "Europe’s epoch of mass killing is overtheorized and misunderstood."

Four pages later, however, Snyder notes the insufficiency of facts and the necessity of theory. "The important question is: how could (how can) so many lives be brought to a violent end?" Overtheorizing is not the problem; mistaken theorizing is, at least in the long run. Repeating his findings about empire, reoccupation and collaboration, Snyder, however, finally turns mostly to wise reflections on memory and current European identity. And he concludes with the antitotalitarian humanist’s interest in individuals, leaving aside for the future the search for explanation.

The "bloodlands" in which political murder took place is a historical reality but also a historian’s construction. It is a prism through which to view a refractory landscape—in Snyder’s case a literal one—in order to understand it better. Constructions help see things in relation to others, but always on pain of exclusion. As one chooses one’s insight, one chooses one’s blindness.

Of course, like genocide, "the Holocaust" is also a construct devised to make sense of the past. It came into widespread circulation as late as the ’70s, disengaging the spectacular killing of Jews from the wartime scene and distinguishing their destruction from the suffering of "humanity" that ideologies like antifascism presented as the truth of the twentieth century. Different constructions of the Holocaust continue to vie for supremacy even today; a new book by Dan Stone, Histories of the Holocaust, provides a state-of-the-art analysis of the different current approaches. So the real question is how to compare the rival constructions and use the comparison to see what is valuable and problematic about each one.

Snyder doesn’t note the stress that his treatment of partisans places on the notion of "civilian atrocity." He shows vividly that in and around Minsk, and in the horrific occupation of Warsaw, Jews and others were real (not imagined) insurgents, and the Nazis responded in classically brutal fashion. Those Jews and other Belarussians and Poles were not "civilians," and their very prominence unsettles the framework in which civilian depredations are the focus. For that matter, Snyder doesn’t pause to defend his premise that noncombatant depredations should be isolated, historically and morally, from the legitimate violence of warfare. Despite the staggering tote board of death Snyder erects, most of the blood spilled during World War II in these bloodlands came from soldiers’ bodies. Yet the war is present in his history of them only as context for the death of civilians (or of those Soviet POWs, whose killing is illegitimate according to the law of armed conflict). Focusing on so-called political murder—as if war were not political—makes sense given the conventional assumption that when soldiers die it is simply a part of the cost of states’ doing business, whereas civilian atrocity falls into a different category. But a dead body is a dead body, and if geography is to provide the framework it is hard to understand why these hecatombs of young men don’t count too.

Similarly, Snyder’s worry that Auschwitz gets too much press compared with the Aktion Reinhard camps like Treblinka is persuasive, but only up to a point, and it may not justify the relegation of the vast Auschwitz complex to a kind of afterthought on the grounds that it does not snugly fit the geographical framework. Situated on the western fringes of the bloodlands, on territory the Soviets never touched until they liberated it, Auschwitz faced not only west but south, toward the Hungarian Jews who would die there en masse in 1944, with no experience of Soviet occupation. In a somewhat perfunctory three pages on the site, Snyder spends more time minimizing it—relatively few Polish Jews died there, lots of others survived—than acknowledging its climactic significance, beyond any qualifications and rectifications.

Observing that 90 percent of the fatalities in the bloodlands had occurred before Birkenau came online in the spring of 1943, Snyder beautifully calls Auschwitz "the coda to the death fugue." But for a historian who so frequently cites facts and figures as dispositive, it still matters that more Jews died in Auschwitz—about a million—than in any other camp. And much more important, Auschwitz, more than any other site, revealed the continental scope of Hitler’s hatred of Jews, which far transcended the bloodlands even if the suffering there was worse, both relatively and absolutely. In this sense, Auschwitz marks the limits of Snyder’s revisionism, for choosing Auschwitz as a synecdoche of the whole Holocaust is far less an error than making the Gulag the symbol of Stalinist crime.

Ultimately, Snyder’s main achievement is his juxtaposition of two homicidal regimes to make a point so well as to make it unanswerable, when not long ago it still elicited howls of outrage for trivializing the unique fate or special honor of particular victims. "Attention to any single persecuted group," as Snyder says, "will fail as an account of what happened in Europe between 1933 and 1945." This does not mean that connections among the various spasms of killing can be easily established; and noting their geographical proximity, as Snyder does, provides a series of local insights that may not add up to a comprehensive explanation. Still, by any measure Bloodlands is a remarkable, even triumphant accomplishment.