BAGHDAD, Iraq (AP) - U.S. and Iraqi troops launched a major offensive against insurgents in Baghdad's western Abu Ghraib district late Sunday, and aides to a radical anti-American Shiite cleric worked to defuse tensions caused by a recent spate of sectarian killings. Amid the violence, Iraq's government demanded that Syria do more to stop foreign fighters from crossing the porous border and a senior Iraqi Trade Ministry official was killed in an ongoing terror campaign that has killed more than 550 people in less than one month. Iraqi authorities also announced that Ghazi Hammud al-Obeidi, 65, one of the most-wanted...