The title of David Levering Lewis's surprising new book, God's Crucible, brings to mind another piece of ceramic phrasing, Colin Powell's warning to President Bush about invading Iraq: "You break it. You own it." The people and the land of Iraq that we now own as occupiers can be counted among the shards, but the invasion and occupation have also wreaked havoc on a culture, a country's history, and its religion. For better or worse, every American needs to have a certain working knowledge of the traditions of the Middle East, not only for the momentous task of putting the pieces back together in Iraq, but also to avoid such nightmares in the future and to judge the overheated rhetoric of politicians in the forthcoming American election.