originally Middle East Treaty Organization or Baghdad Pact Organization
Mutual-security organization, originally composed of Turkey, Iran, Iraq, Pakistan, and Britain.
It was formed in 1955, at the urging of the U.S. and Britain, to counter the threat of Soviet expansion into the Middle East. CENTO was never very effective. Iraq withdrew after its anti-Soviet monarchy was overthrown in 1959. In that same year the U.S. became an associate member, and CENTO's headquarters were moved to Ankara, Tur. After the fall of Mohammad Reza Shah Pahlavi in 1979, Iran withdrew and CENTO was dissolved.