Gulf Cooperation Council (GCC), officially Cooperation Council for the Arab States of the Gulf, organization (est. 1981) promoting stability and economic cooperation among Persian Gulf nations. Its members are Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and the United Arab Emirates. In 1991 the GCC countries joined with Egypt and Syria to create a regional peacekeeping force. An aid fund was also established to promote development in Arab states; it was used to help liberate Kuwait in 1991. In 2003 GCC members eliminated tariffs on trade between member nations and established common external tariffs. They have agreed to establish a broader economic union (including a single market and currency; Oman and United Arab Emirates have opted out); a common market was established in 2008. During the national protests in 2011 known as the Arab Spring, the GCC sent forces into Bahrain in support of its monarch, and attempted to negotiate a resolution in Yemen.