The creation of the Baghdad Pact was another significant development in the institutionalization of the Cold War insofar as it extended the goal of militarily containing the Soviet Union far into the Middle East. Established in 1955 after an agreement between Turkey and Iraq, it also included Britain, Pakistan, and Iran. As a rule, the general purpose of this pact was to prevent the spread of communism into the Middle East and keep the Soviets away from vital Middle East oil. Yet following the overthrow of anti-Soviet rule in Iraq in 1959, the Pact began to crumble. Iraq immediately left the organization, and when the US joined as an associate member, its name was changed to the Central Treaty Organization (CENTO).