BAGHDAD, Nov. 21 -- Senior U.S. military commanders in Iraq say it is increasingly likely they will need a further increase in combat forces to put down remaining areas of resistance in the country.
Convinced that the recent battle for Fallujah has significantly weakened insurgent ranks, commanders here have devised plans to press the offensive into neighborhoods where rebels have either taken refuge after fleeing Fallujah or were already deeply entrenched.
But the forces available for these intensified operations have become limited by the demands of securing Fallujah and overseeing the massive reconstruction effort there -- demands that senior U.S. military officers say are likely to tie up a substantial number of Marines and Army troops for weeks.
"What's important is to keep the pressure on these guys now that we've taken Fallujah from them," a high-ranking U.S. military commander said, speaking on condition he not be named because of the sensitivity of the deliberations on adding more troops. "We're in the pursuit phase. We have to stay after these guys so they don't get their feet set."
The possibility that additional troops would be required to battle the insurgency in this critical period preceding the Iraqi elections, scheduled for Jan. 30, has been signaled for weeks. The Pentagon took an initial step in this direction last month, ordering about 6,500 soldiers in Iraq to extend their tours by up to two months.
With some fresh U.S. forces already arriving in Iraq as part of a long-scheduled rotation, and two newly trained Iraqi brigades due to start operating next month, U.S. military leaders had hoped to avoid further increases.
But over the past week, a closer assessment of the forces needed for the Fallujah recovery effort and future offensive operations revealed a gap in desired troop strength, at least over the next two or three months, according to several officers familiar with the issue.
The officers said the exact number of extra troops needed is still being reviewed but estimated it at the equivalent of several battalions, or about 3,000 to 5,000 soldiers. The number of U.S. troops in Iraq fell to nearly 100,000 last spring before rising to 138,000, where it has stayed since the summer.
To boost the current level, military commanders have considered extending the stay of more troops due to rotate out shortly, or accelerating the deployment of the 3rd Infantry Division, which is scheduled to start in January. But a third option -- drawing all or part of a brigade of the 82nd Airborne Division on emergency standby in the United States -- has emerged as increasingly likely.
Hinting at this possibility at a Pentagon news conference on Friday, Lt. Gen. Lance Smith, the deputy chief of U.S. Central Command, recalled that airborne forces were deployed to Afghanistan on a short-term basis to bolster military operations. Smith noted, however, that the Afghan case was "a little bit different" because "we had a very small number of forces to begin with" there.
If airborne units were rushed to Iraq, commanders here said, they likely would not be used in the offensive actions being planned, given their lack of heavy armor and their unfamiliarity with the targeted neighborhoods. Rather, their purpose would be to take over policing and other functions in Baghdad's International Zone, where American and top Iraqi government officials work. That would free locally seasoned units of the 1st Cavalry Division for such actions.
Much of the division's 2nd Brigade, which had been patrolling Baghdad, was shifted to Fallujah for the battle there earlier this month and remains unavailable for action elsewhere. This situation is the cause of much of the pressure for reinforcements.
"We feel that we need to keep the 2nd Brigade out there longer than we had originally thought, so we're not going to have all the flexibility we wanted in December," one senior military officer here said.
Some senior officers have worried that any move to bring in more U.S. troops could be perceived as a sign of U.S. vulnerability in the face of the tenacious insurgency or as a vote of no confidence in the ability of Iraq's new security forces to fill the gap. It also could fuel the U.S. political debate over whether the Bush administration has committed enough forces to secure Iraq.