In 1948, the Soviets tried to force the western allies out of Berlin by a blockade of the western sectors. The Soviets blocked roads, railways and waterways, but the Potsdam Agreement guaranteed air corridors to Berlin. Because the western allies flew in all the supplies that normally came by land, the Berlin Blockade is also known as the Berlin Airlift. The Blockade ended in May 1949. By the end of 1949, two new states had been created out of occupied Germany - the Federal Republic of Germany (West Germany) in the West and the German Democratic Republic (East Germany) in the East - with West Berlin an enclave that was not part of either.