It was the response during 1948 and 1949 to the Soviet blockade of West Berlin. After World War II (1939–45), the German city had been divided into four occupation zones: American, British, French, and Soviet. But following the conclusion of the war, it did not take long for the Cold War (1947–89) between the Western powers and the Soviet Union to heat up. When the Americans, British, and French agreed to combine their three areas of Berlin into one economic entity, the Soviets responded by cutting the area off from all supply routes. In June 1948 all arteries—road, rail, and water—into West Berlin were blocked by Soviet troops. Since Berlin was completely surrounded by the Soviet occupation zone, the Soviets clearly believed the blockade would be an effective move that would prompt the Western countries to pull out. But the move failed: the Americans, British, and French set up a massive airlift. For the next eleven months, West Berlin was supplied with food and fuel entirely by airplanes. The Soviets lifted the blockade in May 1949, and the airlift ended by September.