In 1946 Winston Churchill defined the realities of post-war Europe and etched an image in the world's imagination: "an iron curtain has descended across the Continent. Behind that line lie all the capitals of the ancient states of Central and Eastern Europe ... This is certainly not the liberated Europe we fought to build up, nor is it one which contains the essentials of permanent peace."
Martin Sixsmith argues, "there were genuine fears that Stalin had designs on the West, but the allies had a crucial advantage: the atomic bomb." The motherland was defenceless and Stalin exhorted Igor Kurchatov, leader of the Soviet nuclear programme: "Build us an atomic weapon in the shortest possible time! You must build the bomb to save us from a grave danger." Kurchatov called his team 'soldiers' in a new scientific war. They were driven hard and lived under the threat of reprisals if they failed to deliver. Then on the 29th of August 1949, the Soviet Union exploded its first atomic weapon in the deserts of Kazakhstan. Neither side could now prevail unscathed.
When the Western Powers merged their half of divided Germany into a new semi-independent state, the Federal German Republic, the Soviet sector became a separate, socialist state and to underline the split, the Soviet authorities halted all Western shipments into Berlin, an "island of capitalism in a sea of communism" which irritated Stalin. It was the first flashpoint of the post war years and Khrushchev later said Stalin was "prodding the capitalist world with the tip of the bayonet". But he hadn't counted on the West's determination. The Berlin airlift forced Stalin to capitulate. On the 12th of May 1949, Moscow lifted the blockade but it left a legacy of bitterness and mistrust. The Cold War had begun.
Historical Consultant: Professor Geoffrey Hosking
Producers: Anna Scott-Brown & Adam Fowler
A Ladbroke Production for BBC Radio 4.