The cabin door was flung open and, to the tattoo of drums and the snap of swastika flags flapping in a sharp wind, Neville Chamberlain stepped into Hitlerland.

A few hours later, the prime minister was standing in Hitler’s enormous Berchtesgaden office, admiring the Wagnerian view; across the valley, a range of high mountains was half shrouded in a late-afternoon mist. He turned and examined the office. There was a huge globe next to the desk and an oak conference table at the far end of the office. “I have often heard of this room, but it is much larger than I expected,” Chamberlain said, hoping to ease the tension with a little small talk.

“It is you who have big rooms in England,” Hitler replied. Then, having exhausted his store of small talk, he demanded the return of the Sudetenland.

“I’d rather be beat than dishonored,” Alexander Cadogan, permanent secretary at the Foreign Office, said upon hearing that Chamberlain had acquiesced to Hitler’s demand. In the days following the prime minister’s return to London, there was much talk of national honor in certain quarters of Whitehall, Westminster, and the press. But what was national honor to “he that died on Wednesday”? To Chamberlain, such talk only led to more Sommes and Passchendaeles. The Sudeten crisis had to be viewed through the lens of national interest. Was it worth going to war for a small country on the other side of Europe? The prime minister did not believe it was, and it quickly became apparent that most of the British public agreed with him, as did the dominions: Australia, New Zealand, South Africa, and especially Canada. “I approve wholeheartedly of the course [Chamberlain] has adopted,” said Mackenzie King, the Canadian prime minister. After several weeks of intense pressure from the British and the French, who also favored a peaceful resolution of the crisis, the Czechs agreed to cede to Germany the regions of the country that were more than 50 percent ethnically German. On September 22, Chamberlain returned to Germany, expecting to sign an agreement. Instead, Hitler handed him a new set of demands: incorporation of the Sudetenland into the Reich and the annexation of several strategic regions beyond the German-speaking parts of Czechoslovakia.

“Hitler has given Chamberlain the double cross . . . [And] it looks like war,” William Shirer, the CBS correspondent in Berlin, wrote on the twenty-third. By the end of the week, Shirer’s premonition seemed about to come true. The British fleet and the RAF were on full alert, searchlights scanned the London sky, every significant building in the imperial capital was cordoned off with sandbags, territorials (reservists) were digging trenches in Hyde Park and St. James Park, and the government was requisitioning cellars and basements as air raid shelters. Shocked Londoners felt as if they had stepped through the looking glass into Things to Come. This “is like a nightmare in a film,” Rob Bernays, a junior government minister, wrote. “We are like people waiting for Judgment.” At a dinner party, Bernays made a joke to lighten the somber mood and was immediately cut off by another guest, who snapped, “Damn you! [Don’t] you realize we may be dead next week?”

Meanwhile, in Downing Street, Chamberlain was facing a cabinet revolt. After explaining at some length his indignant reaction to Hitler’s new terms, he recommended that the terms be accepted. This was too much, even for Lord Halifax, the foreign secretary and Chamberlain’s closest ally in the cabinet. “Personally, I believe Hitler has cast a spell over Neville,” he told a colleague. Other cabinet members felt that Chamberlain had been undone by his vanity. And, unquestionably, Chamberlain’s desire to be hailed as a peacemaker did cloud his judgment, though other factors also went into his thinking. On September 20, two days before Chamberlain returned to Germany, a memo by General Hastings Ismay of the Imperial General Staff had counseled prudence: If “war with Germany has to come,” Ismay wrote, “it would be better to fight her in, say, 6 to 12 months than to accept the present challenge.”

In late September, the Czech crisis resolved itself at the Munich Conference, which was convened at Mussolini’s suggestion and was the source of some of the most evocative images of the prewar years: There is a famous photo of Chamberlain, looking more the coroner than the undertaker as he poses reluctantly for photographers in front of the two-engine Lockheed Electra that will fly him to Germany. There is one of Édouard Daladier, the French premier, at the Munich airport, looking physically massive but with vacant eyes that suggest that the premier’s nickname, the Bull of Vaucluse, may overstate the case; and there is one of Hitler standing at the conference table, his expression a compound of all his favorite words: “unshakable,” “invincible,” “triumphant,” “decisive”; and there is one of Mussolini, arms crossed, head tilted at an odd angle to hide the mole on his bald skull. And the most famous photo of all: Chamberlain, on his return from Munich, standing in front of a bank of microphones, promising “peace in our time” under a gray autumn sky. Lost among the lesser footnotes of the Munich Conference are two appeals from President Roosevelt, one urging Hitler to attend the conference, the other an appeal for a peaceful resolution of the Sudeten crisis.

Such was the residual strength of Never Again, not just in Britain but globally, that the morning after promising “peace in our time,” Chamberlain awoke to find himself a world hero. In Munich, Germans, some with tears in their eyes, flocked to the hotel where the prime minister had stayed, like pilgrims to a shrine. In France a subscription was raised to build the prime minister a country house and a trout stream.