The Second World War, in its full detail, from the rise of Nazism through the Holocaust to the war's end and its immediate aftermath, is the subject of a separate forty-episode series that this book deliberately does not duplicate.
This chapter's purpose is narrower and specific to this book's own argument: to trace the direct lines connecting the war to the previous chapters, particularly the unresolved consequences of the peace examined in chapter forty six, and to identify what made this catastrophe different in kind, not merely in scale, from the wars and atrocities examined throughout the rest of this book.
Chapter forty six ended with a caution against reading the Treaty of Versailles as a simple, sufficient cause of what followed. That caution still holds. But several direct lines do run from that settlement into this one, and they are worth tracing plainly.
The stab-in-the-back myth and the broader sense of national humiliation examined in the previous chapter gave Hitler's movement a ready-made grievance to organise around, from its earliest days. The Great Depression, beginning in 1929, then did more than any single political factor to convert that grievance into mass electoral support. It drove German unemployment to catastrophic levels. And it collapsed the fragile Weimar Republic's political centre, in favour of parties, communist and Nazi alike, that rejected both the republic and the settlement it had signed.
It is worth adding one further, uncomfortable connection to earlier chapters. The pseudo-scientific racial theories Nazi ideology drew on, ranking human populations hierarchically by supposed biological worth, did not originate with Hitler. They descended, in a direct and traceable line, from the same nineteenth-century European racial science examined in chapter thirty three's account of the Enlightenment's own blind spots, and from the colonial administrative practices examined in chapter forty four, which had already applied comparable hierarchies of human worth to non-European populations for decades before Nazi ideology turned the same apparatus on a European minority.
Hitler became chancellor in January 1933 through a legal, if manipulated, political process rather than through a coup, and within months used a fire at the German parliament building as pretext to secure emergency powers, ban rival parties, and establish the one-party dictatorship that followed, dismantling the same democratic constitution the stab-in-the-back myth had always treated as illegitimate in the first place.
Between Hitler's 1933 seizure of power and the war's outbreak in September 1939, a series of diplomatic decisions by Britain and France, decisions this book's own concerns make worth tracing even while it defers the war itself to another account, repeatedly declined to confront escalating German violations of the Versailles settlement examined in chapter forty six.
Germany's rearmament from 1935, its remilitarisation of the Rhineland in 1936 in direct violation of the treaty, and its annexation of Austria in 1938, were each met with protest but no serious countermeasure, a pattern of accommodation that came to be known as appeasement, and that reflected a genuine and, in the aftermath of the previous chapters' account of the war's origins, understandable horror among British and French publics at the prospect of repeating the catastrophe of 1914.
The pattern reached its clearest expression at the Munich Conference of September 1938, where Britain and France, without consulting Czechoslovakia itself, agreed to Germany's annexation of the Sudetenland, a German-speaking Czechoslovak border region, in exchange for Hitler's assurance that this represented his final territorial demand in Europe, an assurance British Prime Minister Neville Chamberlain announced to cheering crowds on his return as having secured peace for our time, a phrase that has since become a byword for the dangers of believing an aggressor's own stated limits.
Germany occupied the rest of Czechoslovakia within six months, demonstrating the assurance's worthlessness, and then, in August 1939, signed a non-aggression pact with the Soviet Union, its supposed ideological arch-enemy, containing secret protocols dividing Poland and the Baltic states between them, a cynical arrangement that removed Germany's fear of a two-front war and cleared the path for the invasion of Poland weeks later that finally triggered British and French declarations of war.
Europe had seen conquest, occupation and mass killing before, across nearly every chapter of this book. What distinguished Nazi Germany's project was not any single atrocity in isolation but a specific combination: an industrialised, bureaucratically organised programme of extermination, targeting Jews specifically as a matter of stated racial ideology rather than as an incidental consequence of war or conquest, planned and executed with the same administrative thoroughness examined, in far more benign contexts, throughout this book's account of European state-building.
It is worth being precise about scale here, because the number is easy to state and hard to actually hold in mind. Six million is roughly the population of a large European capital city, and it represented, in most of the countries where the killing was most thorough, the near-total destruction of communities that had lived in those specific towns and regions for many centuries, a rupture of continuity, examined earlier in this book across chapters on Jewish life under medieval and early modern rule, that has no equivalent recovery in the decades since.
The Holocaust murdered approximately six million Jews, alongside Roma, disabled people, political prisoners, gay men and others deemed racially or socially undesirable by Nazi ideology, through a system of ghettos, mass shootings, and purpose-built extermination camps whose sole function was industrialised killing, a system without precedent in either its ideological rationale or its administrative method, however much earlier chapters of this book have documented genocidal violence in other forms and contexts.
This is not a claim that earlier atrocities examined in this book, the Herero and Nama genocide of chapter forty four among them, were lesser crimes. It is a claim that the Holocaust's specific combination of industrial method and totalising racial ideology, applied to an entire continent's Jewish population through a purpose-built bureaucratic and technical apparatus, represents a distinct historical phenomenon that later international law, developing the very concept of genocide partly in direct response to it, has treated as requiring its own specific category of understanding and prevention.
The war killed an estimated seventy to eighty-five million people worldwide, the deadliest conflict in human history by a wide margin, and left Europe divided in ways that echoed, while also fundamentally transforming, the divisions examined throughout this book's earlier chapters on nationalism, empire and ideological conflict.
The physical destruction across the continent was staggering by any previous measure in this book. Cities across Germany, Poland, the Soviet Union and beyond had been reduced substantially to rubble by bombing and by ground combat. Tens of millions were displaced from their homes, whether by direct expulsion, by the westward shifting of Poland's own borders at the Soviet Union's insistence, or by flight from advancing armies, producing a refugee crisis whose scale dwarfed anything examined earlier in this book, including the displacements following the partitions of Poland in chapter thirty five.
Germany, defeated unconditionally this time, in contrast to the ambiguous 1918 armistice examined in the previous chapter, was occupied and divided among the victorious Allied powers, a division that hardened, within a few years, into the two separate German states and the broader continental split examined in the next chapter.
It is worth naming, too, what did not end in 1945 for millions of Europeans themselves. Soviet forces that had liberated much of Eastern Europe from Nazi occupation did not withdraw once the fighting stopped, and the political arrangements they imposed across Poland, Hungary, Romania, Bulgaria and the eastern portion of Germany itself replaced one set of foreign domination with another, a continuity of unfreedom for the populations involved that the war's standard narrative of liberation tends to understate, and that is the direct subject of the next chapter.
The war also finally and definitively ended the European colonial empires examined in chapter forty four, not through any single decision but through the practical exhaustion of the colonial powers themselves, the ideological delegitimisation of racial hierarchy that the war against Nazism made difficult for European powers to maintain with a straight face regarding their own colonial subjects, and the accelerating independence movements that the war years had, in many colonies, directly strengthened.
One consequence belongs in this book specifically, because it changed the legal and institutional vocabulary every later chapter in this book must use.
The word genocide itself did not exist before 1944. It was coined by the Polish-Jewish lawyer Raphael Lemkin, who had lost dozens of family members in the Holocaust, combining a Greek word for race or tribe with a Latin word for killing. He coined it specifically to describe what he had witnessed. He spent years afterward lobbying for it to be recognised in international law, an effort that succeeded in 1948 when the United Nations adopted the Genocide Convention, a document this book has already had occasion to invoke, in chapter forty four's discussion of the Herero and Nama, precisely because Lemkin's term gave later historians a legal category with which to name atrocities that had previously gone undescribed by any single agreed word.
The Nuremberg trials of 1945 and 1946 tried surviving senior Nazi leaders for war crimes, crimes against humanity and crimes against peace. They established a related and equally consequential principle. Following orders was not, by itself, a legal defence against prosecution for participating in mass atrocity. That doctrine has shaped the prosecution of war crimes and genocide in every conflict examined by international courts since.
Both innovations, the word and the legal doctrine, exist because of this specific catastrophe, and both have been applied, with varying success and consistency, to atrocities examined throughout this book and to others that occurred after it, a reminder that this chapter's brevity should not be mistaken for a judgment that the war's legal and conceptual legacy was itself minor.
This chapter has not attempted to narrate the war's military campaigns, its individual battles, or the full scope of Nazi atrocities and Allied responses, all of which receive far fuller treatment in the dedicated series this book explicitly defers to.
What it has tried to do is narrower and, for this book's purposes, more important: to show that the war did not arrive from nowhere, that its roots run directly through the unresolved grievances of chapter forty six, and that its consequences, examined in the following three chapters, reshaped nearly every institution and boundary this book has spent its previous chapters describing.
A final caution belongs here rather than at any other point in this book. It is tempting, and it is also a serious historical error, to treat the Second World War as this book's true subject and everything before it as mere preamble, or everything after it as mere epilogue. Each of the previous forty-six chapters concerned people who did not know, and could not have known, that this catastrophe was coming, and each of the following four chapters concerns people building a genuinely new order, not merely recovering from the old one. This book has tried, throughout, to resist writing history backward from known endings, and that discipline matters here more than anywhere else in it.