No agreement could be reached with the Soviets on continued control of Germany. When the Allies decided to introduce a new currency into West Germany to counter inflation, the Soviets opposed the move. As a response, and as a means of stopping the reunification of Western Germany, the Soviets imposed a blockade on Berlin on June 18th 1948 , which had been and remained under four-power control.

The American Commander in Germany, General Clay, stated that if the Soviets managed to push the U.S. out of Berlin, the next step could be the expulsion of the U.S. from Germany and then from Europe altogether. He suggested that the U.S. break the blockade by force. President Truman decided on an airlift. The airlift was very successful, and the Soviets lifted the blockade eleven months after it was imposed.

Tensions over the future of Germany increased between the United States and the Soviet Union. When no agreement could be reached, the Western Allies met on June 1 in London and announced their intention of setting up a separate county as West Germany. On June 18, a new currency was introduced in West Germany. The Soviets responded by cutting rail links to West Berlin, which was occupied by the US, British and French.

According to President Truman, “what the Russians were trying to do was to get us out of Berlin. At first, they took the position that we never had a legal right to be in Berlin. Later they said we had the right but that we have forfeited it.

The Soviet response to issuing a new currency was to introduce new money of their own. When the West blocked its use in West Berlin, the Soviets cut off all land connections to Berlin. General Clay, who commanded US forces in Germany, immediately began bringing essential supplies by air. After discussing the situation with his cabinet on June 26, 1948, President Truman ordered that this Adhoc airlift be converted into a full-scale airlift using all US Air Force transportation capacity.

The airlift was a success. It lasted until May 12, 1949. Over the 11 months, 2.3 million tons of food and other supplies were transported in a total of 277,000 flights. Eleven airmen were killed in accidents. The Soviets lifted their airlift and achieved none of their goals. West Berlin stayed firmly under western control, and West Germany began to develop as an independent country.