The Austrian émigré writer Stefan Zweig composed the first draft of his memoir, “The World of Yesterday,” in a feverish rapture during the summer of 1941, as headlines gave every indication that civilization was being swallowed in darkness. Zweig’s beloved France had fallen to the Nazis the previous year. The Blitz had reached a peak in May, with almost fifteen hundred Londoners dying in a single night. Operation Barbarossa, the colossal invasion of the Soviet Union by the Axis powers, in which nearly a million people would die, had launched in June. Hitler’s Einsatzgruppen, mobile killing squads, roared along just behind the Army, massacring Jews and other vilified groups—often with the help of local police and ordinary citizens.

Zweig himself had fled Austria preëmptively, in 1934. During the country’s brief, bloody civil war that February, when Engelbert Dollfuss, the country’s Clerico-Fascist Chancellor, had destroyed the Socialist opposition, Zweig’s Salzburg home had been searched for secret arms to supply the left-wing militias. Zweig at the time was regarded as one of Europe’s most prominent humanist-pacifists, and the absurd crudity of the police action so outraged him that he began packing his things that night. From Austria, Zweig and his second wife, Lotte, went to England, then to the New World, where New York City became his base, despite his aversion to its crowds and abrasive competitiveness. In June of 1941, longing for some respite from the needs of the exiles in Manhattan beseeching him for help with money, work, and connections, the couple rented a modest, rather grim bungalow in Ossining, New York, a mile uphill from Sing Sing Correctional Facility. There, Zweig set to furious work on his autobiography—laboring like “seven devils without a single walk,” as he put it. Some four hundred pages poured out of him in a matter of weeks. His productivity reflected his sense of urgency: the book was conceived as a kind of message to the future. It is a law of history, he wrote, “that contemporaries are denied a recognition of the early beginnings of the great movements which determine their times.” For the benefit of subsequent generations, who would be tasked with rebuilding society from the ruins, he was determined to trace how the Nazis’ reign of terror had become possible, and how he and so many others had been blind to its beginnings.

Zweig noted that he could not remember when he first heard Hitler’s name. It was an era of confusion, filled with ugly agitators. During the early years of Hitler’s rise, Zweig was at the height of his career, and a renowned champion of causes that sought to promote solidarity among European nations. He called for the founding of an international university with branches in all the major European capitals, with a rotating exchange program intended to expose young people to other communities, ethnicities, and religions. He was only too aware that the nationalistic passions expressed in the First World War had been compounded by new racist ideologies in the intervening years. The economic hardship and sense of humiliation that the German citizenry experienced as a consequence of the Versailles Treaty had created a pervasive resentment that could be enlisted to fuel any number of radical, bloodthirsty projects.

Zweig did take notice of the discipline and financial resources on display at the rallies of the National Socialists—their eerily synchronized drilling and spanking-new uniforms, and the remarkable fleets of automobiles, motorcycles, and trucks they paraded. Zweig often travelled across the German border to the little resort town of Berchtesgaden, where he saw “small but ever-growing squads of young fellows in riding boots and brown shirts, each with a loud-colored swastika on his sleeve.” These young men were clearly trained for attack, Zweig recalled. But after the crushing of Hitler’s attempted putsch, in 1923, Zweig seems hardly to have given the National Socialists another thought until the elections of 1930, when support for the Party exploded—from under a million votes two years earlier to more than six million. At that point, still oblivious to what this popular affirmation might portend, Zweig applauded the enthusiastic passion expressed in the elections. He blamed the stuffiness of the country’s old-fashioned democrats for the Nazi victory, calling the results at the time “a perhaps unwise but fundamentally sound and approvable revolt of youth against the slowness and irresolution of ‘high politics.’ “

In his memoir, Zweig did not excuse himself or his intellectual peers for failing early on to reckon with Hitler’s significance. “The few among writers who had taken the trouble to read Hitler’s book, ridiculed the bombast of his stilted prose instead of occupying themselves with his program,” he wrote. They took him neither seriously nor literally. Even into the nineteen-thirties, “the big democratic newspapers, instead of warning their readers, reassured them day by day, that the movement . . . would inevitably collapse in no time.” Prideful of their own higher learning and cultivation, the intellectual classes could not absorb the idea that, thanks to “invisible wire-pullers”—the self-interested groups and individuals who believed they could manipulate the charismatic maverick for their own gain—this uneducated “beer-hall agitator” had already amassed vast support. After all, Germany was a state where the law rested on a firm foundation, where a majority in parliament was opposed to Hitler, and where every citizen believed that “his liberty and equal rights were secured by the solemnly affirmed constitution.” ...