Economic Cooperation Organization (ECO), an organization that promotes economic and cultural cooperation between states. Established in 1985, its original members were Iran, Pakistan, and Turkey. The conclusion of the Soviet war against Afghanistan in 1989 and the breakup of the Soviet Union in 1990 created both economic and strategic opportunities for extending the ECO into Central Asia. In 1992 Afghanistan and the six Islamic republics of the former Soviet Union—Azerbaijan, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan—became members of the organization.

Sharp political and cultural differences between Turkey and Iran have limited the progress of the ECO. Turkey enjoys ethnic and linguistic ties to most of the Islamic nations of the former Soviet Union. Since 1992 Turkish companies have invested heavily in the oil-producing regions of Kazakhstan and Azerbaijan. Turkey has also presented itself as a bridge between the financial markets of Europe and the Islamic states of Central Asia. In advocating regional cooperation in Central Asia, it holds up the European Union (EU) as a model.

By contrast, Iran views the ECO as a commonwealth of Islamic states bound together by religious and cultural similarities. Iran offers a model of religious and cultural militancy for the ECO, such as that of Shia Muslims in neighboring Azerbaijan and ethnic Iranians in Tajikistan. In Central Asia, this model appeals to many Muslims who resent the influence and power of ethnic Russians in the region. The future direction of the ECO therefore depends largely on the balance of power between Turkey and Iran.