Have those seeking to make sense of Middle Eastern politics by concentrating on radical Islam neglected the long-lived intra-Islamic confrontation between Sunnis and Shiites? If so, this book offers compelling corrective reading. Nasr provides a succinct summary of Shiite religious precepts and practices and of how Sunnism differs from Shiism, theologically and sociologically. He identifies and locates the different Shiite communities and then, with a good mix of broad-brush interpretative history and anecdotal detail, sketches the history of Sunni-Shiite confrontation from Lebanon to South Asia, making a strong case for the depth of this divide. At the same time, he does not suggest some sort of incipient Shiite International -- the important differences among Shiite communities and the limits of transnational Shiite political loyalties are clear. Still, the thrust of this broad-ranging and detailed, but still eminently readable, account is that the recent political gains of the Shiites may be ushering in a major, perhaps even tectonic, shift in the larger Middle Eastern political landscape.