This report discusses Iran’s influence over the post-Saddam government in Iraq, which is substantial because the predominant parties in that government have long enjoyed Tehran’s sponsorship. An emerging concern is that Iran’s influence has extended to support for militant groups in Iraq. Some U.S. statements and press sources say that sophisticated explosive devices are entering Iraq from Iran, suggesting that Iran, or factions within Iran, are backing Iraqi factions that use violence to oppose the U.S. and allied military presence in Iraq.