U.S. ambassador says Iraq must act faster in establishing a new government

Some Iraqi and U.S. officials see dangerous parallels between the current impasse and the one that followed the 2005 vote, when feelings of Sunni disenfranchisement helped fuel the worst period of the insurgency.

"We are facing a dangerous slippery slope," said Atheel al-Nujaifi, a leading figure in the Iraqiya slate. "No one can predict its consequences."

In 2006, Sunni extremists began attacking Shiite militias by using powerful bombs. Similar attacks in recent weeks, including Friday's bombings targeting Shiite worshipers, have raised fears that Shiite militias could once again take up arms in areas where residents feel abandoned by the government.

Unlike in the period after the 2005 elections, the current political disputes have been largely peaceful. Iraqi and U.S. officials say an outbreak of political violence is less likely now because Iraq's security forces are stronger and less politicized than they were in 2006. But many say a lengthy period of government paralysis raises the probability of a new outbreak of violence.

"Right now the violence is not a strategic threat to the state," said Brett McGurk, a fellow at the Council on Foreign Relations who served as a senior Iraq adviser to the Bush and Obama administrations. "If there is a sense that the drivers of violence are political parties, then you start to have the seeds of a breakdown."

Special correspondent Jinan Hussein contributed to this report.