American reservists (search)are stressed "nearly to the breaking point" with repeated and extended deployments in wars in Afghanistan and Iraq, some lawmakers said Wednesday.

House Armed Services Committee Chairman Duncan Hunter, (search R-Calif., said recent moves to find more combat soldiers for Iraq — including the use of troops who normally train others — could "mortgage the future" of the nation's military and warned that the "elasticity of the force" needs to be preserved.

He noted that the ratio of Reserve to active duty soldiers in Iraq is increasing and said he was concerned troops aren't getting enough time back in the states in between deployments.

"I'm worried ... worried for them, for asking very few to exert an enormous sustained effort for the good of all of us," added Missouri Rep. Ike Skelton (search), said ranking Democrat on the panel.

The committee was hearing testimony on troop rotations (search) in Iraq and Afghanistan, looking with particular interest at Reservists and at a move made last week by the Defense Department to call back soldiers who have already served.

For the first time in more than a decade, the Army is forcing thousands of former soldiers back into uniform, a reflection of the strain on the service of long campaigns in Iraq and Afghanistan. More than 5,600 former soldiers — mostly those who recently finished serving and have skills in military policing, engineering, logistics, medicine or transportation — will be assigned to National Guard and Reserve units that are scheduled to deploy to Iraq or Afghanistan.

Perhaps thousands more are likely to be called up next year, the Pentagon said.

The new call-up is the first sizable activation of the 111,000-member Individual Ready Reserve (search) since the 1991 Gulf War, though several hundred people have voluntarily returned to service since the Sept. 11, 2001 terror attacks.

"Accessing the IRR to obtain the right soldiers for specific requirements allows us to minimize cross-leveling between units, thereby protecting other units for future requirements by maintaining their cohesion — a critical force multiplier in combat," Gen. Richard Cody, Army vice chief of staff, said in prepared remarks before the committee.

Cody said that within a week, the Army will begin deploying 5,600 IRR soldiers. Already, 2,300 soldiers have been deployed from this unit in the War on Terror.

People in the Individual Ready Reserve are distinct from the National Guard (searchand Reserve because they do not perform regularly scheduled training and are not paid as reservists. They are eligible to be recalled in an emergency because their active duty hitches did not complete the service obligation in their enlistment contracts.

Stretched by war needs, the Pentagon has declared a "stop-loss" to prevent the separation of troops who have finished their obligation. The Army is so stretched for manpower that in April it broke a promise to some active-duty units, including the 1st Armored Division, that they would not have to serve more than 12 months in Iraq. It also has extended the tours of other units, including some in Afghanistan.

"We're taxing our part-time soldiers, our Guard and Reserves nearly to the breaking point," said Skelton. "We have to be aware that the families back home are paying a significant price. We don't want to break the force."

But David S.C. Chu, undersecretary of defense for personnel and readiness, testified that much care is taken in thinking about such issues as date and duration of last deployment before troops are deployed, and said only if assets from around the globe can't be obtained are more U.S. troops used.

In Afghanistan and Iraq, several things are taken into consideration when deploying troops, including that forces do not spend more than one year "boots on the ground," don't exceed more than 24 months cumulative mobilization time and make sure all military sectors contribute resources equally.

"We are also employing a number of innovative force management practices to meet the challenge of current operations," Chu said, adding that Congress could help by enacting legislation "to improve flexibility in personnel management."

Critics say the stop-losses and dipping into the Individual Ready Reserve amounts to conscripting people to fight in Iraq. Some say the military needs a permanent increase in troops.

The Associated Press contributed to this report.