Questions of timing emerge on Iraq offensive

President Bush said Friday that the offensive answered critics who have accused Iraqi Prime Minister Nouri Maliki's Shiite Muslim-dominated government of inaction and of favoritism toward Shiites.

"I would say this is a defining moment in the history of a free Iraq," Bush said at the White House.

"The decision to move troops, Iraqi troops, into Basra talks about Prime Minister Maliki's leadership."

But some of the administration's allies have begun to question the timing and wisdom of the offensive, which has met with stiff resistance since it was launched Tuesday in the southern city of Basra. Since then, fighting against Shiite militiamen has spread through much of southern Iraq and into Baghdad. Iraqi forces have called in U.S. airstrikes to fend off well-armed groups in Basra, including an attack by a Navy jet on a mortar position.

Signifying the potential difficulty ahead, other U.S. assets, including special-operations forces and spy planes, are expected to join the fight.

Within the Pentagon, officers expressed concern about the rapid spillover of violence into areas where U.S. forces have spent more than a year painstakingly working to restore order, especially the Shiite neighborhoods of Baghdad.

U.S. officials have long believed that Iraqi militias should be disbanded. But military analysts inside and outside the Pentagon are questioning whether this was the time and place to do it.

The offensive comes two weeks before Army Gen. David H. Petraeus is to testify before Congress on his plans for Iraq.

Petraeus is known for opening his recent presentations by displaying what aides call his favorite slide: a chart showing attacks in Iraq spiking last year, then dramatically dropping amid the deployment of 28,500 additional U.S. troops.

Pentagon officials worry that the recent violence will mar that otherwise compelling narrative.

The extra troops are scheduled to leave by the end of July, and Petraeus is expected to make a recommendation on whether and how fast troops should be sent home after that.