Many tales have been told of the fight over Berlin and rest of Germany after the fall of the Nazis at the end of World War 2. The allied forces of Britain, the United States, France and the Soviet Union carved the country up. But soon Berlin became a different kind of battle-ground for their pre-war hostilities to return. It's a story brought vividly to life again by Giles Milton's latest book Checkmate in Berlin: The Cold War showdown that shaped the modern world.