THE WAR in Iraq has profoundly changed the Middle East, although not in the ways that Washington had anticipated. When the U.S. government toppled Saddam Hussein in 2003, it thought regime change would help bring democracy to Iraq and then to the rest of the region. The Bush administration thought of politics as the relation ship between individuals and the state, and so it failed to recognize that people in the Middle East see politics also as the balance of power among communities. Rather than viewing the fall of Saddam as an occasion to create a liberal democracy, therefore, many Iraqis viewed it as an opportunity to redress injustices in the distribution of power among the country's major communities. By liberating and empowering Iraq's Shiite majority, the Bush administration helped launch a broad Shiite revival that will upset the sectarian balance in Iraq and the Middle East for years to come. There is no such thing as pan-Shiism, or even a unified leadership for the community, but Shiites share a coherent religious view: since splitting off from the Sunnis in the seventh century over a disagree ment about who the Prophet Muhammad's legitimate successors were, they have developed a distinct conception of Islamic laws and practices. And the sheer size of their population today makes them a potentially powerftil constituency. Shiites account for about go percent of Iranians, some 70 percent of the people living in the Persian Gulf region, and approximately 50 percent of those in the arc from Lebanon