In March 1940, in an unremarkable Birmingham University office, German-born physicist Rudolf Peierls and his Austrian-born colleague Otto Robert Frisch wrote a memorandum. In it they argued that a small quantity of uranium could be used to produce a chain reaction, releasing a force equivalent to many thousands of tons of TNT. The wartime government of Winston Churchill realised the potential of their discovery and soon the highly secret MAUD Committee was created to help advance their work. The committee concluded that a nuclear weapon was feasible and this led to a project with the codename Tube Alloys.
But the scale of the work required was very challenging for Britain and there was fear that any testing site would be in range of the Luftwaffe. So the preliminary work was made available to the US and soon became a key part of America’s own pre-existing Manhattan Project. Under the Quebec Agreement, the two nations agreed to share the results – although in the end the US would become most reluctant to do so.
At the ‘Big Three’ Yalta summit of 1944, Stalin requested and received explicit signs from the Americans that the western allies would agree to his complete control of Eastern Europe. In return he promised Roosevelt that he would join the war against Japan. Churchill thought that his frail American partner had been outmanoeuvred.
In fact – although undeniably frail (he would die aged just in April 1945, less than a month before VE Day) – Roosevelt got exactly what he came for, a reduction in the blood price of defeating Japan. The more Soviet troops that could be brought to bear in the east, the lower US casualties would be. “This makes the trip worthwhile,” he told his Chief of Staff Admiral William Leahy.
Would the American president have been so keen to make this deal had he known that an atomic bomb was now only months away? Perhaps not, but at that stage nobody in Washington – of the miniscule number who had even heard about it – could be sure that the Manhattan Project would ever lead to a viable military device. And the nearer the Americans got to Japan’s ‘home islands’, the harder the enemy fought. Peleliu, just seven by three miles, had taken 10 weeks to capture. Another island, Iwo Jima, which was invaded that February, had become a byword for brutality.
On April 1, 1945, US troops landed on Okinawa in the largest amphibious assault of the entire Pacific campaign. Kamikaze bombers rained down on British and American warships, while fighting on the ground was the most violent yet. When it was finally captured in July, half the civilian population was dead. The prospect of invading Japan weighed heavily on Allied leaders: a battle that could take years and kill millions more people.
It was why General Eisenhower had been so reluctant to drive on Berlin – he needed to preserve manpower. It was also why the victory speeches of Churchill and Truman on VE Day were remarkably sombre considering the magnitude of the victory in Europe. The PM explicitly warned of the ongoing battle against Japan. “We may allow ourselves a brief period of rejoicing,” he said, “but let us not forget for a moment the toils and efforts that lie ahead.”
Harry S Truman, who had become 33rd US president following the death of Roosevelt, was even more subdued. “Our victory is only half over,” he told the American people. Full, final victory came on August 15, 1945, three months after VE Day. In the event, the atomic bomb was viable. Devastatingly so.On August 6, 1945, a US Air Force Boeing B-29 Superfortress named Enola Gay, after the mother of its pilot, Colonel Paul Tibbets, dropped the “Little Boy” device on Hiroshima at approximately 8.15am.
After falling for 44.4 seconds, it detonated over the city at an altitude of 1,968ft, making it the first nuclear weapon used in the history of warfare. Three days later on August 9, a second, more powerful device, Fat Man, was dropped over Nagasaki by a B-29 named Bockscar. News of the bombs transfixed the planet.
More than 200,000 people died in just two explosions, many more were terribly injured and two cities were utterly devastated. Everybody understood that a new and frightening age had begun. Japan’s surrender was announced by Emperor Hirohito on August 15, 1945 – now VJ Day in the UK – and formally signed on September 2, ending the Second World War after six years and a day. But the attacks, no matter how horrifying, had undoubtedly saved many millions more lives.
Subsequently, Truman did not feel obliged to honour promises made by his predecessor and so – to the frustration of Britain’s new Prime Minister, Clement Attlee – Anglo-American co-operation on nuclear research was quickly wound down.British scientists were told they could no longer use research documents they themselves had created only weeks before.
The Soviet Union would go nuclear in 1949 – having received more assistance from the US programme through its nuclear spies than the British had as formal allies. The UK would have to pursue a weapon of its own – and it took six years until an explosion at Monte Bello Island in Western Australia announced the arrival of the world’s third nuclear-armed nation.
