Berlin Airlift Map
In a May 12, 1945 letter to President Harry Truman, British Prime Minister Winston Churchill expressed his concern about the "iron curtain" separating Western Europe from Soviet controlled areas. Growing tensions between the Allies and the Soviets escalated in 1948, with frequent road closures and inspections of Allied transports into Berlin. The introduction of a new currency for Western Germany and Berlin -- the Deutsche Mark -- on June 23, 1948 was the tipping point. Soviets cut power to Berlin and set up a blockade preventing any land access into the city.