Details

Albert Einstein writes to president Roosevelt, telling him that it would be possible to build an atomic bomb.

US scientists begin work on an atomic bomb – Russian spies immediately begin sending detailed technical data to the NKVD.

President Roosevelt authorises the building of an atomic bomb.

Russian scientist Georgii Flerov warns Stalin that western scientists are developing an atomic bomb.

The US government sets up the ‘Manhattan Project’ to develop an atomic bomb.  Robert Oppenheimer is appointed Scientific Director.

Stalin authorises the development of an atomic bomb and puts Kurchatov in charge.  At first he is not shown the NKVD’s spy reports; the work is underfunded, and progresses slowly.

It is decided to use the first atomic bomb on Japan.

Soviet spy Klaus Fuchs is transferred to work on the Manhattan project; he supplies detailed information to the NKVD.  The NKVD does not act because they did not understand the mathematics!

Americans capture Tinian (Japan within bombing range)

Americans capture Iwo Jima but with huge losses; the Japanese defenders resist fanatically.

US identifies Hiroshima as the target city.

Germany surrenders – end of the war in Europe.

Tokyo destroyed by US firebomb raid; Japan does not surrender.

First Japanese offer (through their ambassador in Russia) about making peace.

Potsdam Conference

‘Trinity’ test at Alamogordo, New Mexico successfully tests an atomic detonation.  J. Robert Oppenheimer says: "I am become death, the destroyer of worlds." 

155 Manhattan Project scientists petition Truman to give Japan an opportunity to surrender before he uses the Bomb.

Truman tells Churchill about the Bomb; they agree to tell Stalin.

Stalin tells Truman and Churchill that the Japanese had asked for peace.

Truman authorises use of the Bomb.

Truman tells Stalin that the US has "a new weapon of unusual destructive force."  Stalin appears not to understand the implications, but immediately orders Soviet scientists to invent their own atomic bomb.

Truman insists on a military target (later it was claimed that Hiroshima was a military target).

The Potsdam Declaration calls upon Japanese "to proclaim now the unconditional surrender of all Japanese armed forces." 

On the same day, the Japanese again tried to arrange peace negotiations through their ambassador in Moscow.

Japan officially rejects the Potsdam Declaration

Truman informed that the Japanese were again asking for peace

Hiroshima; Truman  calls it ‘the greatest day in history’

Russia enters the war in the Pacific, a week ahead of schedule.

Nagasaki

Japan surrenders