Well, so much for the whole 72 virgins thing and the radical Islamist desire to die in martyrdom: The story tonight in Iraq is not the arrival of more U.S. troops, but the departure of one of the country's most powerful men, Moqtada al Sadr and members of his army. According to senior military officials al Sadr left Baghdad two to three weeks ago, and fled to Tehran, Iran, where he has family. Al Sadr commands the Mahdi Army, one of the most formidable insurgent militias in Iraq, and his move coincides with the announced U.S. troop surge in Baghdad....