The U.S. ambassador to Iraq advocated a mix of “pressure and engagement” on Thursday to persuade countries like Iran and Syria to help quell the violence in Iraq as a roadside bomb killed four U.S. soldiers. The comments by U.S. Ambassador Zalmay Khalilzad suggested the U.S. State Department plans to continue a conversation about Iraq with Iran, which it accuses of training and arming Iraqi militants who have attacked U.S. forces. Full Story