Despite that 22 percent, General William Caldwell insisted violence and progress exist side by side, rattling off statistics such as more that 700 weapons caches discovered since July.
But the fact that the insurgency can take loses like that and still step up its attacks against American troops in what it believed to be an attempt to influence the November elections in the United States is also a measure of its strength and resilience, reports CBS News national security correspondent David Martin.
"The enemy knows that killing innocent people and Americans will garner headlines and create a sense of frustration," Caldwell said.
The spike in violence during the month of fasting was "disheartening" and the Americans were now working with Iraqi authorities to "refocus" security measures, Caldwell said.
"In Baghdad, Operation Together Forward has made a difference in the focus areas but has not met our overall expectations in sustaining a reduction in the level of violence," Caldwell said at a weekly news briefing.
Meanwhile, the White House is emphatically rejecting two proposals aimed at ending the war in Iraq. Press Secretary Tony Snow says the idea of dividing Iraq into Sunni, Shiite and Kurdish regions is a "non-starter." He also says a phased withdrawal of U.S. troops — perhaps by five percent every two months — is not under consideration. "You withdraw when you win," Snow said.
Snow was commenting on ideas reportedly being looked at by a blue-ribbon panel chaired by former Secretary of State James Baker. The commission is to report its findings after the elections. But Baker has said there are alternatives other than "stay the course and cut and run."
In other developments:
The gloomy assessment of the Baghdad operation, which was set in motion with the deployment of an extra 12,000 U.S. and Iraqi troops on Aug. 7, was issued at a time of perceived tension between the U.S. military and administration and the nearly five-month-old government of Prime Minister Nouri al-Maliki.
Caldwell said, for example, that U.S. forces had been forced to release a captured top organizer for radical Shiite cleric Muqtada al-Sadr on Wednesday, a day after he was detained on suspicion of "illegal" activities.
He said Mazin al-Sa'edi, a top organizer with the Sadr Movement political party in western Baghdad, was set free on the demand of al-Maliki. Al-Sa'edi had been detained along with five of his aides for suspected involvement in Shiite militant violence.