Western allies began an airlift after the soviets began a blockade of this city.
bonn
boston
bosnia
berlin

Berlin

Explanation:

The blockade of Berlin was the closing of the borders that shared the United Kingdom and the United States with the Soviet Union in the occupied German territory, and that developed between June 24, 1948 and May 12, 1949. It was imposed by the Soviet Union, and affected mainly the western area of Berlin, then controlled by the forces of the United States, the United Kingdom and France. It was applied in response to the monetary reform imposed by these countries. The first two decided to supply the western part of the city through the three air corridors that were legally required to allow the USSR through its territory. The blockade, which lasted eleven months, was lifted by the Soviet Union on May 12, 1949.