Central Treaty Organization

Central Treaty Organization (CENTO), mutual defence and security organization that functioned between 1959 and 1979. It evolved from the earlier Middle East Treaty Organization (METO), which in turn had succeeded the Baghdad Pact of 1955. The purpose of the organization was to provide joint defence against possible aggressors and to encourage the economic and scientific development of the member nations: Iran, Pakistan, Turkey, and the United Kingdom. The name CENTO was adopted in 1959 after Iraq, originally a signatory, withdrew from the Baghdad Pact; CENTO referred to a central area between regions included in the North Atlantic Treaty Organization, to which Turkey belongs, and the now defunct South East Asia Treaty Organization, of which Pakistan was a member. Although not an official member of CENTO, the United States actively supported the organization. Its headquarters, originally established at Baghdad, was moved to Ankara, Turkey, after the pro-Western Iraqi government was overthrown in 1958.

Following the Islamic revolution in Iran in 1979, the new Iranian regime announced its intention to withdraw from CENTO. Shortly afterwards, Pakistan also left the organization, arguing that Iran's withdrawal had deprived it of any meaning. This rendered CENTO defunct.