CENTO began with a series of treaties of mutual cooperation between the United States, Pakistan, and Turkey in 1954 and a military assistance agreement with Iraq in the same year. In 1955 Turkey and Iraq signed a mutual defense treaty creating the foundation for the Baghdad Pact. In the same year Britain, Iran, and Pakistan joined the Baghdad Pact, which guaranteed economic and military assistance to any country in the pact that was threatened by communism.
In 1958 a coup in Iraq ousted the pro-Western government, and the following year Iraq withdrew from the treaty, prompting the change of its name to the Central Treaty Organization. The effectiveness of CENTO was lessened during the Indo-Pakistani Wars of 1965 and 1971; neither party to the treaty rushed to assist Pakistan even though India was at the time an ally of the Soviet Union.
Following the overthrow of the proWestern Pahlavi dynasty and the establishment of the Islamic Republic of Iran in 1979, Iran also withdrew from CENTO. Along with the failure of CENTO members to assist Pakistan, the withdrawal of Iran and Iraq from the treaty led to the treaty’s demise.