On April 10, 2003, as the world watched a statue of Saddam Hussein come crashing down in the heart of Baghdad, a mob of looters attacked the Iraq National Museum. Despite the presence of an American tank unit, the pillaging went unchecked, and more than 15,000 artifacts--some of the oldest evidence of human culture--disappeared into the shadowy worldwide market in illicit antiquities. In the five years since that day, the losses have only mounted,...