In August 1954 the Communist People’s Republic of China attacked several islands located a few miles from mainland China in the Taiwan Strait that were held by the Nationalist Republic of China.
In January 1955, the Formosa Resolution was approved by the U.S. Congress authorizing President Eisenhower to use U.S. forces to defend Nationalist China and its possessions in the Taiwan Strait against armed attack. The U.S. Navy then assisted the Nationalists in evacuating their forces from the Tachen Islands.
In March 1955, U.S. Secretary of State John Foster Dulles stated that the U.S. was seriously considering a nuclear strike against Communist China. In response, the alliance of NATO foreign ministers warned against such action.
In May 1955, Communist Chinese forces ceased shelling Kinmen and Matsu Islands, but the fundamental issues of conflict remained unresolved and both sides subsequently built up military forces on the Taiwan Strait leading to a new Taiwan Strait crisis three years later.
Source: Wikipedia