"Bush's January announcement that he had ordered a second aircraft carrier battle group to the Persian Gulf and would share Patriot air-defense missile systems with U.S. allies in the region raised fears that the Iraq war could spread. So have its accusations that Iran is supplying advanced explosives to Shiite Muslim militias inside Iraq.
American-led raids have led to the arrests of several Iranians, and the administration has authorized the use of deadly force against suspected Iranian agents in Iraq. But Snow said the issue is being dealt with as a force-protection measure within Iraq."