Which US action was the most direct response to the Soviet blockade of West Berlin?

(Reuters) - This week marks the 60th anniversary of the start of the Berlin airlift. Below is the history and some facts behind the western allies’ response to the Soviet blockade of West Berlin:

AFTERMATH OF WORLD WAR TWO:

-- In September 1944, World War Two allies Britain, Soviet Union and United States signed London Agreements on zones of occupation when Germany was defeated and the war ended. Berlin was to be divided into sectors. France was also later assigned a zone and a sector.

-- On May 2, 1945 Soviet troops captured Berlin and the Third Reich surrendered five days later. British and U.S. occupation troops arrived in July and French troops in August.

EAST-WEST TENSIONS:

-- By 1948 cold war tensions mounted between the Soviet Union and the Western Allies, originally over elections but subsequently over the introduction of a new currency in West Germany which the Russians declined to accept in Berlin.

-- In March 1948, the Russians left the Allied Control Authority governing all Germany. On April 9, 1948, Soviet leader Josef Stalin ordered all American Military personnel maintaining communications equipment out of the Eastern Zone (Soviet controlled Berlin).

-- The Soviet Union walked out of the Kommandatura, the four-power administration of the city in June 1948.

THE BLOCKADE AND AIRLIFT:

-- Soviet forces blocked all traffic to the three western sectors, starting the Berlin blockade on June 24.

-- In response, western allies launched an airlift of essential supplies to West Berlin. At its peak the airlift brought in a plane every one to two minutes.

-- In total, the U.S. delivered 1,783,573 tonnes, while 541,937 tonnes were delivered by the British totalling 2.3 million tonnes from 277,569 flights to Berlin.

-- The skies over Germany were crowded with up to 300 aircraft en route to or from Berlin at given times.

-- Planes were taking off and landing in West Berlin every 90 seconds on average. They brought coal, fuel, newsprint, medicines, nappies, powdered milk, dried vegetables, ambulances and even an entire power plant in small pieces.

THE END:

-- Soviet dictator Josef Stalin called off the blockade in 1949 when it became clear the only chance of making it work would be to attack the airlift. This would have invited war with the United States, an unacceptably dangerous option for the Kremlin.

-- It reopened land routes on May 12, 1949 and on September 30 the airlift was officially ended.

Sources: Reuters/Peguin Dictionary of 20th Century History/ here