Berlin Blockade
The 1948–1949 Soviet blockade of West Berlin's land access, answered by the Western Allies' year-long airlift of supplies into the city.
Deutsche Mark: The West German currency introduced in June 1948 as part of monetary reform in the western occupation zones. Its introduction without Soviet approval in Berlin triggered the blockade within days.
Berlin Airlift: Operation Vittles and allied flights delivering coal, food and medicine into West Berlin from June 1948 to September 1949. The Western answer to the blockade; its logistics decided the crisis.
NATO: The North Atlantic military alliance founded in April 1949 by the United States and Western European states. Negotiations accelerated during the blockade; the alliance was signed before it ended.
Lucius D. Clay: US military governor in Germany, who ordered the airlift against advice and refused to abandon Berlin. Clay pushed the airlift option and even considered an armed convoy on the autobahn.
Second Berlin Crisis: Khrushchev's 1958 ultimatum demanding a free West Berlin, resolved without another blockade. The sequel crisis tested whether the West would defend Berlin again.
Currency reform of 1948: The replacement of the Reichsmark with the Deutsche Mark in the western zones, ending four-power monetary control. The reform applied to West Berlin, giving the Soviets their stated grievance for cutting access.
Tempelhof Airport: Berlin's central airfield, whose runways carried a large share of the airlift's landings. Landing intervals under three minutes made the airlift's tonnage figures possible.
Federal Republic of Germany: The West German state founded in May 1949 from the three western occupation zones. The blockade's end cleared the way for founding the western state weeks later.
Ernst Reuter: West Berlin's mayor, whose radio appeals for help rallied Western and Berlin public opinion. His December 1948 appeal, broadcast worldwide, pressed the Allies to keep flying.
Korean War: The 1950–1953 war between North and South Korea that hardened NATO military planning. Coming a year after the blockade, it confirmed that air supply alone would not always suffice.