The fate of the free world hung in the balance. Stalin’s Soviet Union sought to drive the Western democracies from Germany to continue the communist advance across Europe. The first step in Stalin’s scheme was to bring Berlin under Soviet control. Berlin was situated deep inside the Soviet-occupied region of the country, but the German capital had been divided into two halves, one of which was occupied by the Soviet Union, the other, in separate sectors, by Britain, France and the USA. Stalin decided to make the Allied hold on West Berlin untenable by shutting down all the overland routes used to keep the city supplied.