How, when, and why the Nazis’ decision to exterminate Europe’s Jews was made remains one of the most vexed and disputed of all important questions concerning the Holocaust. There was not simply an order from Hitler commanding the killing of the Jews, and there is general agreement that the genocide evolved in stages, steadily becoming more comprehensive. The Origins of the Final Solution by the universally respected historian Christopher R. Browning, now at the University of North Carolina at Chapel Hill, is a magisterial examination of this subject in the wider context of the overall evolution of Nazi policy towards the Jews between the outbreak of the Second World War in September 1939 and the opening of the first extermination camps early in 1942.

Browning’s massive but highly readable work (some parts of which were written by the German scholar Jürgen Matthäus) covers every aspect of this question and incorporates all significant previous research. While new interpretations are, of course, likely to be offered in the future, it is most unlikely, barring the discovery of new documents of great importance, that we will ever have a clearer picture of this process than the one Browning offers. This is not to say that the evolution of Nazi policy towards the Jews in this period is now crystal clear”it emphatically is not”but it is to say that all the evidence that an historian can bring to bear on this question has now been synthesized in the clearest form it is ever likely to have.

To those whose knowledge of the Holocaust consists, essentially, of the fact that Hitler killed the Jews, it often comes as a surprise to learn that, in the first seven and a half years of Nazi rule in Germany, he did no such killing: Jews were not deliberately murdered by the Nazi regime until the invasion of the Soviet Union in June 1941. In Karl Schleunes’ famous phrase, there was a “twisted road to Auschwitz,” with a gradual but by no means direct path to continental genocide. For the first few years of Nazi rule in Germany”Hitler came to power in January 1933 as chancellor and consolidated his rule after the death of President von Hindenburg a year later”Nazi policy aimed “merely” at the removal of Jews from positions of authority, especially in the state sector, with such removal constantly reinforced by the totalitarian regime’s propaganda and its police terrorism.

While Jews began to flee abroad from the first days of the Nazi regime, only after Kristallnacht in November 1938 did Nazi policy switch categorically to the expulsion of all Jews from the Reich as its central aim. Although the Jews were ever-more intensively disemployed, defined as noncitizens, ostracized, stripped of wealth, brutalized, and encouraged to emigrate, they were not being killed by the government, and the majority of Germany’s five hundred thousand Jews managed to escape from the country before the outbreak of the war (though not necessarily to safety, as many wound up trapped in Poland and the Soviet Union). Indeed, so effective were the Nazis at expelling the Jews from their territories that about two-thirds of Austria’s two hundred thousand Jews managed to flee abroad in the short period between the German takeover of Austria in March 1938 and the closing of the borders to further Jewish emigration from the Reich in 1940-1941.

From the Kristallnacht pogrom onwards, Nazi policy toward the Jews radicalized relentlessly, reaching deliberate continental genocide of a kind never before seen in history by 1941-1942. It is here, however, that considerable difference of opinion among historians begins. Over the past twenty years or so, a consensus has emerged that Hitler did not embark on his campaign of killing all Jews in the Soviet Union, including women and children, immediately after the invasion began in June 1941, but only several months later. At first, it seems, only adult male Jews and “commissars” (Soviet state operatives) were killed; one of the best-known recent expositions of this viewpoint is Philippe Burrin’s 1994 Hitler and the Jews: The Genesis of the Holocaust . Nearly all of the detailed documentation of the Holocaust, including recently discovered records, points to this conclusion. Nonetheless, by the end of 1941, Nazi killing squads ( Einsatzgruppen ) had killed hundreds of thousands of Jews in the western Soviet Union, murdering men, women, and children indiscriminately. Beginning in early 1942, the extermination camps (all located in conquered Poland) began to murder Jews, and others, brought in from all parts of Europe.

Perhaps the main area of dispute about this process concerns Hitler’s precise role in ordering the killing of the Jews. Remarkably, we simply do not know, in an unequivocal way, what Hitler’s precise role was. The dictator often gave oral orders to senior henchmen such as Heinrich Himmler that were never written down, and historians can only infer Hitler’s precise role and intentions from evidence which is infuriatingly inadequate and contradictory. Because of the lack of unambiguous evidence, historians have been divided for decades, rather misleadingly, into so-called “intentionalists,” who argue that Hitler always intended to kill the Jews, and “functionalists,” who claim that the killing process somehow, as it were, welled up from local SS units in Russia until it became general Nazi policy.

It might be noted that, to a surprising extent, much about Hitler’s precise knowledge of the Holocaust remains unclear. For instance, we do not know if Hitler ever saw photographs or newsreels of the killing process, or, indeed, just how comprehensive and brutally frank were Himmler’s reports to Hitler. We have agendas of face-to-face meetings between Hitler and Himmler, at which the Holocaust was to be discussed, but no memorializations or minutes of such meetings. Most of the senior Nazis who were tried at Nuremberg in 1945-1946 (few of whom had any immediate involvement in the killing of Jews) had apparently never seen photographic evidence of the horrors of the concentration camps until their trials; they appeared to be genuinely shocked when newsreels of Belsen and Buchenwald were shown to the court.

Browning wrestles with these and many other related questions in a consistently persuasive and cogent way. He concludes, very sensibly, that it is inconceivable that the Holocaust, unprecedented in history and entailing a massive, counterproductive diversion of resources in wartime, could have taken place without Hitler’s immediate knowledge and approval, although his orders were often, as Browning notes, “vague and inexplicit.” Moreover, Hitler himself was the chief Nazi ideologue of rabid, demented, racialist anti-Semitism, with anti-Semitism at the very center of his worldview and in and of itself a central motivating factor in his foreign and military policies.

Browning also notes that the destruction of the Jews went hand-in-hand with a much wider attempt at “ethnic cleansing” throughout Eastern Europe. The Nazis had well-advanced plans, which might have been realized had they won the war, to remove by force millions of Poles and other Slavs to Siberia, with vast numbers certain to die en route. One of the major merits of Browning’s book is its detailed discussion of these plans, as well as Nazi policies towards the gypsies. Browning notes, correctly, that the Nazis killed large numbers of gypsies even though Hitler hardly ever mentioned them and certainly did not have anti-gypsy hostility at the heart of his ideology. Browning also offers a detailed consideration of the Nazi program of murdering the physically and mentally handicapped among “Aryan” Germans (the “T4 program”), which began in mid-1939 and eventually claimed seventy thousand victims before it was stopped in mid-1941, and he reports that many of the killers in the T4 program went on to be directly involved with the extermination of the Jews in Eastern Europe.

Browning concludes that Hitler ordered the genocide of the Jews in the Soviet Union during the period of what he terms “euphoria” just after the invasion of Russia, when victory appeared to be easily within Germany’s grasp. Browning dates this, as most recent historians do, to August-October 1941, in the context of a general “war of destruction” in the Soviet Union. Browning’s timetable thus reflects today’s consensus, although he does present a comprehensive array of evidence in support of this conclusion. With the failure of the German armies to gain a decisive victory in Russia, a failure that was becoming evident by October or November 1941, Nazi genocide began to turn toward the Jews under German control throughout Europe, beginning with the Jews of Poland, and employing the assembly-line techniques of the gas chambers in extermination camps like Treblinka and Auschwitz rather than the open-air shootings that the Einsatzgruppen invariably used during the first days of the invasion.

Browning’s account of the evolution of the Nazi genocide is the most comprehensive that has yet appeared, and it is no exaggeration to say that the author, who offers here 110 pages of endnotes, has read and absorbed every available document of relevance. Yet one must continue to wonder whether Hitler really waited until August-October 1941 to decide on a policy of genocide. Hitler habitually thought in demographic and social-Darwinist terms, and from 1939 onwards, he was confronted by a new demographic reality”that he now had many millions of Jews under his thumb, far more than the mere five hundred thousand in Nazi Germany in 1933, a figure itself ever-diminishing through emigration. With the conquest of western Poland in mid-1939, over two million Jews came under his rule, while the invasion and conquest of the Soviet Union would add another five million, entirely apart from the many Jews in Nazi satellite states such as Hungary and Romania. It is very difficult to believe that Hitler did not contemplate genocide along with the invasion of the Soviet Union, given the fact that he would soon have the ability to get rid of all of Europe’s Jews in one fell swoop. As Browning carefully notes, as early as February 1941 Hitler remarked to a number of other top Nazis that towards the Jews “he was thinking of many things in a different way, not exactly more friendly.”

Browning also examines the much-debated question of the degree of complicity by ordinary Germans in the “Final Solution.” Here he sensibly steers a middle course between those who see genocide as carried out by the top Nazis, under the smokescreen of the war, secretly and in a way almost totally hidden from Germany’s civilians, and, at the other extreme, historians such as Daniel J. Goldhagen who view virtually the entire German people as complicit in “exterminationist anti-Semitism.” Browning realizes the extent to which anti-Semitism, although al­ways present in German (and, more obviously, in Austrian) culture, had nevertheless been greatly ameliorated down to 1933 by the general and continuous rise of liberalism and “modernity.” But he also understands that Germany’s “special path” to the twentieth century”unlike that of the English-speaking world”involved a reactionary and anti-liberal elite masterminding and benefiting from an extremely rapid industrial revolution while holding to ultranationalism and expansionism as its core values. The attitude of the average German towards the persecution of the Jews by the Nazis (that is, in Nazi Germany itself) was arguably one of reprehensible indifference; but one must not forget also that Nazi Germany was a totalitarian society, where opposition to the regime meant certain imprisonment or death, and that the Nazis kept their killings in Eastern Europe a secret from their own people.

Ultimately, one must surely conclude that the unparalleled enormities carried out by the Nazis took place because the First World War destroyed Germany’s traditional elite structure, permitting, in the context of the Depression, the rise of an extremist movement at the absolute fringes of political life which would never otherwise have come to power. Almost precisely the same thing occurred, for the same reasons, in Russia with the Bolshevik revolution and the rise of Stalin to supreme power just over a decade later. In the English-speaking world, fortunately, the legacy of internalized liberalism, enhanced by the fact that its nations were victorious in the First World War and their institutions left intact, kept the traditional governing structures viable and gave radical fringe groups no opportunity to gather political power. Arguably, too, the deep wound of 1914-1918, which caused so many horrors in Europe, was not fully healed until the fall of Communism in 1990, if even then.

William D. Rubinstein is Professor of Modern History at the University of Wales-Aberystwyth. He is the author of The Myth of Rescue: Why the Democracies Could Not Have Saved More Jews from the Nazis (1997), and Genocide: A History (2004).