U.S. Unsure Who's Behind Iraq Attacks

U.S. commanders say they are unsure about who is responsible for the persistent violence in Iraq, underscoring the challenge they face trying to keep a lid on it amid parliamentary elections this weekend. While security has improved significantly across Iraq in recent years, in the weeks leading up to the March 7 vote, U.S. commanders have reported an increase in low-level violence: kidnappings, assassinations, and mortar attacks against Baghdad's heavily fortified Green Zone, the seat of government power.

And since August, a series of large-scale bombings aimed at government buildings have ripped through Baghdad, killing several hundred people and shaking confidence in Prime Minister Nouri al-Maliki's security services, following the withdrawal of most U.S. combat forces from major Iraqi cities last summer. Commanders worry the violence could spike further after the election if parties feel there was fraud or if negotiations to form a government after the vote break down. U.S. and Iraqi successes cracking down on organized insurgent groups have caused the groups to splinter into an ill-defined web of smaller, often independent, groups with widely divergent motives, ranging from the ideological to the purely material, according to American military officials.