"After instability during the late 1990s, Bahrain undertook substantial political reforms, but lingering tensions between ruling Sunni Muslims and the Shiite majority are re-emerging in advance of October 2006 parliamentary elections. Bahrain's stability has long been a key U.S. interest; it has hosted U.S. naval headquarters for the Gulf for nearly 60 years. In September 2004, the United States and Bahrain signed a free trade agreement (FTA); legislation implementing it (H.R. 4340) was signed January 11, 2006 (P.L. 109-169)."
CRS Report for Congress, 95-1013