Gen. David Petraeus, closely questioned by lawmakers for a second day, described Iraq as a frail state still struggling to provide its own security. That volatile situation figured in his recommendation to President Bush that a gradual pullout of U.S. troops be halted this summer - a recommendation Bush is expected to embrace in a speech Thursday.
But Petraeus also spoke of the burden on U.S. ground forces, and Bush will address that, too. In his speech at 11:30 a.m. EDT, Bush will announce plans to cut the combat tours of active-duty soldiers from 15 months to 12 months. The reduced deployments will not apply - at least initially - to any soldiers currently serving in Iraq, unless conditions improve to the point that commanders believe some could go home early.
Petraeus said, "I am keenly aware of the strain" on the military, noting his own deployment since 2001. "And I can tell you that there is nothing that a commander feels more than, in fact, the losses that we have sustained over there."
His resistance to the idea of any renewed increase of troops for Iraq reflects - at least in part - the reality that the rotation pool of some 1.3 million soldiers and Marines has been exhausted. Army soldiers in particular have faced repeated tours in Iraq and Afghanistan, and senior officers warn that the service's "strategic reserve" is at an all-time low.
U.S. military officials say Petraeus is unlikely to recommend any further cuts until after provincial elections are held in October and that troop strength will not go below 130,000 by the end of the year - about where it was before the surge started, reported CBS News national security correspondent David Martin.
Meanwhile, the chairman of the Joint Chiefs of Staff, Adm. Mike Mullen, says current troop commitments in Iraq make it impossible to send extra forces into Afghanistan.
Andrew Krepinevich, president of the independent Center for Strategic and Budgetary Assessments in Washington, noted that Petraeus' promise to the House Armed Services Committee was a limited one. The four-star general is expected to resign his command position at the end of the year.
While Democratic contenders Barack Obama and Hillary Rodham Clinton have promised voters they would start withdrawing troops if elected, Republican John McCain supported last year's troop increase and believes conditions on the ground should dictate force levels.
Still, Krepinevich said, it's easy to imagine that Army officials agreed to the 2007 buildup on the assumption that Petraeus would give troops a "breather" at some point. Every commander "rotates them out of the line every once in a while to get rested and refitted. Otherwise, you really do burn up the force," he said.
Petraeus wants the U.S. to complete, by the end of July, the withdrawal of the 20,000 troops that were sent to Iraq last year to deal with the violence there. Beyond that, the general proposed a 45-day evaluation period, to be followed by an indefinite period of assessment before he would recommend any further pullouts.
The plan leaves open the possibility that roughly 140,000 U.S. troops will be in Iraq when voters head to the polls this November and Bush leaves office next year.
"We think it makes sense to have some time, to let the dust settle, perhaps to do some adjustment of forces, re-evaluation," Petraeus told House members on Wednesday.
When asked by Rep. Silvestre Reyes, D-Texas, whether he would call for another influx of U.S. troops if security conditions deteriorated during that 45-day window, Petraeus said that would be a last resort.
"That would be a pretty remote thought in my mind," he said.
Instead, the military would try to reallocate existing troops. It also would increase its reliance on Iraqi forces, including highly specialized army and police teams that have been improving in capability, he said.
As on Tuesday, Petraeus faced Democrats and even some Republicans who said they were skeptical Baghdad was doing all it could to calm sectarian violence.
Lacking the votes to order troops home, Democrats plan to push legislation this spring that would force the Iraqi government to spend its own surplus in oil revenues to rebuild the country, sparing U.S. dollars.
Rep. Dana Rohrabacher, a member of the House Foreign Affairs Committee, said he would introduce legislation that would require the Iraqi government pay "for the cost of the security that we're providing them." Under his bill, the stipulation would be written into a legal agreement currently being negotiated with Baghdad on the U.S. military presence in Iraq, called a "status of forces agreement."
"The American people can't carry this load forever, so we're looking forward to a time when someone else can pick up some of it," said Rohrabacher, R-Calif.
Ryan Crocker, the U.S. ambassador in Iraq, said some political progress has been made, but he acknowledged it was slow. Asked what would happen if U.S. troops were to leave in large numbers in the next six months, the ambassador said, "You would see a spiral down, and that would lead to expanded sectarian conflict, levels we have not seen before."