Bahrain, with its three quarters of a million people, may seem a tiny concern, but the island nation is home to the US 5^th Fleet, and has long been one of the outposts of moderation, relative tolerance, and fairly enlightened rule, at least by regional standards. A causeway connects Bahrain to the Saudi mainland, and leisure-minded Saudis often drive there to enjoy pleasures forbidden at home. An acquaintance of mine who used to visit Bahrain quite frequently recalled with fondness the friendly and open attitudes found there toward Westerners.

One faction believes in reconciliation with the Persian Gulf nation's disenfranchised Shiite Muslim majority. The other believes in suppressing Shiite aspirations, even if it means supporting Sunni groups propelled by the same ideologies that inspire Osama bin Laden.

A ranking government official who is a member of the royal family said there was "no doubt" that a hard-line movement existed within the Bahraini power structure.

Even opposition figures say that the most extreme of their nation's Sunnis are moderate compared with Al Qaedainspired insurgents fighting governments in Iraq, Lebanon and Afghanistan. One Sunni hard-liner has said he welcomes the presence of American and British military officials in Bahrain if it keeps the Iranian influence at bay.

Figures allied with the Muslim Brotherhood or more extreme groups have gained the upper hand over the ministries of information, finance and large parts of the military, government critics and human rights groups say. Banks owned by Muslim charities or organizations have grown rich with the return of Arab funds from the United States and Europe after the increased post-Sept. 11 scrutiny of Persian Gulf money in the West. Islamic charities have morphed into powerful political groups, with the government's encouragement, critics say.