The policy applies to soldiers in units due to deploy for the Iraq and Afghanistan wars. The Army said stop-loss is vital to maintain units that are cohesive and ready to fight. But some experts said it shows how badly the Army is stretched and could further complicate efforts to attract new recruits.

"As the war in Iraq drags on, the Army is accumulating a collection of problems that cumulatively could call into question the viability of an all-volunteer force," said defense analyst Loren Thompson of the Lexington Institute think tank.

"When a service has to repeatedly resort to compelling the retention of people who want to leave, you're edging away from the whole notion of volunteerism."

When soldiers enlist, they sign a contract to serve for a certain number of years, and know precisely when their service obligation ends so they can return to civilian life. But stop-loss allows the Army, mindful of having fully manned units, to keep soldiers on the verge of leaving the military.

Under the policy, soldiers who normally would leave when their commitments expire must remain in the Army, starting 90 days before their unit is scheduled to depart, through the end of their deployment and up to another 90 days after returning to their home base.

With yearlong tours in Iraq and Afghanistan, some soldiers can be forced to stay in the Army an extra 18 months.

HARDSHIP FOR SOME SOLDIERS

Lt. Col. Bryan Hilferty, an Army spokesman, said that "there is no plan to discontinue stop-loss."

"We understand that this is causing hardship for some individual soldiers, and we take individual situations into consideration," Hilferty said.

Hilferty said there are about 12,500 soldiers in the regular Army, as well as the part-time National Guard and Reserve, currently serving involuntarily under the policy, and that about 50,000 have had their service extended since the program began in 2002. An initial limited use of stop-loss was expanded in subsequent years to affect many more.

"While the policies relative to the stop-loss seem harsh, in terms of suspending scheduled separation dates (for leaving the Army), they are not absolute," Hilferty said. "And we take individual situations into consideration for compelling and compassionate reasons."

Hilferty noted the Army has given "exceptions" to 210 enlisted soldiers "due to personal hardship reasons" since October 2004, allowing them to leave as scheduled.

"The nation is at war and we are stop-lossing units deploying to a combat theater to ensure they mobilize, train, deploy, fight, redeploy and demobilize as a team," he said.

NO LUCK IN COURT

A few soldiers have gone to court to challenge stop-loss.

One such case fizzled last week, when U.S. District Judge Royce Lamberth in Washington dismissed a suit filed in 2004 by two Army National Guard soldiers. The suit claimed the Army fraudulently induced soldiers to enlist without specifying that their service might be involuntarily extended.

Courts also have backed the policy's legality in Oregon and California cases.

Jules Lobel, a University of Pittsburgh law professor who represented the National Guard soldiers, said a successful challenge to stop-loss was still possible.

"I think the whole stop-loss program is a misrepresentation to people of how long they're going to actually serve. I think it's caused tremendous morale problems, tremendous psychological damage to people," Lobel said.

"When you sign up for the military, you're saying, 'I'll give you, say, six years and then after six years I get my life back.' And they're saying, 'No, really, we can extend you indefinitely.'"

Congressional critics have assailed stop-loss, and 2004 Democratic presidential nominee John Kerry called it "a back-door draft." The United States abolished the draft in 1973, but the all-volunteer military never before has been tested by a protracted war.

A report commissioned by the Pentagon called stop-loss a "short-term fix" enabling the Army to meet ongoing troop deployment requirements, but said such policies "risk breaking the force as recruitment and retention problems mount." It was written by Andrew Krepinevich, a retired Army officer.

Thompson added, "The persistent use of stop-loss underscores the fact that the war-fighting burden is being carried by a handful of soldiers while the vast majority of citizens incur no sacrifice at all."