Berlin in 1948 was an island. The city was deep inside the Soviet occupation zone of Germany, but had itself been divided into four occupation sectors by the victors of the Second World War: American, British, French, and Soviet. The three Western sectors held about 2.5 million people. They were supplied by road, rail, and canal across more than 150 kilometers of Soviet-controlled territory. When the Western Allies introduced a new currency, the Deutsche Mark, in their occupation zones in June 1948, the Soviets responded by closing the surface routes into West Berlin. No trains. No trucks. No barges. Stalin's calculation seemed simple. The Western powers could not feed two and a half million people by air. They would have to evacuate or surrender Berlin to Soviet control. American General Lucius Clay, the military governor of the U.S. zone, had already considered driving an armed convoy down the autobahn to break the blockade by force. Wiser heads in Washington and London worried that this would mean war. Instead, the Royal Air Force began flying supplies into West Berlin on 26 June. The Americans started two days later, in an operation that was officially named Operation Vittles. It was supposed to last a few weeks at most.

It lasted fifteen months. To keep 2.5 million people alive, the airlift had to deliver about 5,000 tons of food, coal, medicine, and supplies every single day. By winter the figure rose toward 12,000 tons. The man who made it work was Major General William H. Tunner, who had organized the Hump airlift over the Himalayas to supply nationalist China during the Second World War. Tunner brought in Tunner's rules: aircraft at three-minute intervals, instrument flight rules at all times regardless of weather, one chance to land in Berlin or you turned around and tried again, no pilot was to leave his aircraft on the ground. He sent jeep snack bars rolling out to the planes as they unloaded. He cut turnaround time to thirty minutes. The airlift used three air corridors: one in from Hamburg in the north, one in from Hanover in the central west, and one outbound to Frankfurt in the south. Aircraft stacked five high above each entry point and peeled off in sequence. By the spring of 1949 the operation had become so efficient that Tunner organized an Easter Sunday push to break records: in the twenty-four hours from noon on 15 April to noon on 16 April, the airlift delivered 12,941 tons of coal in 1,383 flights without a single accident.

There were not enough runways. The two existing airfields at Tempelhof in the American sector and Gatow in the British sector could not handle the traffic. Throughout the autumn of 1948 a third airport was built almost from nothing on the shores of Lake Tegel, in the French sector. French military engineers managed thousands of German laborers, many of them women, who worked day and night to lay the runway by hand because there was no heavy equipment in the city. When they did need bulldozers and graders for the second runway, the machines had to be cut into pieces, flown into Berlin in C-82 Packets, and reassembled. The Tegel runway was finished in under ninety days. It would later become one of West Berlin's principal airports, serving the city for the next sixty years. There was something fitting about the fact that the airport that broke the blockade was built largely by Berliners themselves, civilian volunteers and former refugees, working for a daily food ration.

One hundred and one men died during the operation. Forty were British, thirty-one American; the rest were German workers killed in airfield accidents and crashes. Seventeen American and eight British aircraft crashed during the fifteen months. Each death is still marked at the airlift memorial near Tempelhof, where a tall concrete sculpture rises with three metal prongs reaching west, representing the three air corridors. The names of those who died are listed on the base. The pilots had been bombing Berlin a few years earlier; now they were keeping it alive. Many of them said afterward that the work meant more to them than anything else they had done in uniform. The Berliners, for their part, never forgot. Years later, when American policy on West Berlin turned ambiguous in the 1960s and 1970s, the older generation of West Berliners remembered who had flown for them when nobody else could. The poll numbers reflected it for half a century.

By the spring of 1949 it was clear that the blockade was failing in its purpose. West Berliners had voted overwhelmingly against the Communists in the December 1948 elections; the great majority had refused Soviet offers of free food and ration cards. The airlift had become, as one general put it, a working demonstration that an entire major city could be supplied by air. On 25 April 1949, the Soviet news agency TASS announced that the Soviet Union was willing to lift the blockade. At one minute after midnight on 12 May, the trucks began rolling down the autobahn again. Supply flights continued through September to build up a six-month surplus, in case the Soviets tried again. They did not, at least not in that way. The blockade had hardened American and West European opinion against Stalin, accelerated the formation of NATO, which was signed in April 1949 while the airlift was still flying, and locked in the partition of Germany that would last until 1990. The Federal Republic of Germany was formally founded in May 1949, the German Democratic Republic in October. The lines drawn during the airlift would shape Europe for the next forty years. Tempelhof Airport was closed in 2008 and is now an enormous public park inside Berlin, with the runways still visible and people biking and skating across them. At the end of the central runway, a small museum tells the story of the airlift and the children who waited at the fence in the summer of 1948 for chocolate to fall from the sky.