In political science, triangular diplomacy is a foreign policy of the United States, developed during the Vietnam War (1955–1975) by Henry Kissinger, as a means to manage relations between the contesting communist powers, the Soviet Union and China. Connecting heavily with the correlating policy of linkage, the policy was intended to exploit the ongoing rivalry between the two Communist powers (following the Sino-Soviet split [1956–1966]), as a means to strengthen American hegemony and diplomatic interest.
Interrelating primarily with the subsequent development of the détente era (1969–1979) during the Cold War, triangular diplomacy was instituted in order to prevent the decline of American authority during the Vietnam War following the perceived inefficiencies of George Kennan's defensive policy of containment and Dwight Eisenhower's offensive policy of rollback. Hence, triangular diplomacy was an instrumental facet in the shifting of Cold War policy toward talks of co-operation and diplomacy, and thus set a precedent for the eventual relaxation of tensions between the two superpowers through a focus on mutual benefit (as evidenced in the Strategic Arms Limitation Talks (SALT) and the Strategic Arms Reduction (START) treaties).