The announcement of The Truman Doctrine (a policy aimed at stopping communism) and The Marshall Plan (providing economic aid to European countries, both east and west) by the United States in 1947 caused Stalin further doubt about the Western Allies' intentions. It was in this atmosphere that the Berlin crisis arose.

The Berlin Blockade

Berlin was located completely within the eastern side of Germany which was occupied by the Russians. Britain and the United States unified the western zones of Berlin in 1948, and announced a new currency there. Stalin responded on June 24 by attempting to force the western allies out of Berlin altogether. He cut off rail and road access to the western side of the city.

Airlift at Tempelhot 1949 (Truman Library)

Between June 1948 and May 1949, the Western Allies mounted a massive airlift to keep the western sectors supplied. This broke the blockade. On may 12, 1949 Stalin lifted the blockade and the Cold War was underway.

American cartoon from 1948 (Truman Library)