Lt. Gen. Franklin L. Hagenbeck, the Army's personnel chief, is facing a challenge no American officer has had to contemplate for at least a century: keeping the all-volunteer Army fully manned as it undergoes sustained ground combat.

The United States has not had a draft since 1973. The last time the Army took many casualties without conscript troops was during the war in the Philippines, which lasted from 1899 to 1902, and in which 4,374 U.S. troops died -- five times the toll so far in Iraq.

"We're in uncharted waters, in the sense that we're recruiting and retaining an all-volunteer force in a time of war," Hagenbeck said in a recent interview in his office in the Pentagon.

Right now, Hagenbeck said, indicators on recruiting new soldiers and retaining current ones are good.

For example, 14,611 first-term soldiers have reenlisted this year -- about 98 percent of the Army's goal of having 14,918 of those younger troops re-up by this point.

The numbers for career soldiers are even better, he said. Surveys of intentions of soldiers, and of possible recruits, indicate that target and similar ones for other soldiers will continue to be met. Nor, he said, has the Army had to pull out the stops with bonuses and other incentives to meet personnel goals.

But, he added, "How that will play out over the coming months and years remains to be seen."

The soldiers, he said, are generally doing okay. "There's no question that there's stress on the United States Army -- it would be foolish not to say so." But, he continued, "I think the good news is that by and large, they feel like they're doing something useful, something bigger than themselves, something for the nation."

His biggest worry, said Hagenbeck, a career light infantry officer, is how mothers, teachers and coaches, who influence the youths' enlistment decisions, come to think about military service.

"That's the one I am holding my breath about every day," he said.

Hagenbeck was the commander of the 10th Mountain Division from 2001 to 2003, and during that tour served as deputy commander of U.S. operations in Afghanistan. Then he was chosen to be the Army's personnel chief.

"It's the hardest job I've ever had," he said. "The whole business of a volunteer force is, we've got to make sure we can man and maintain a volunteer Army in the difficult environment we have right now."

The reason he was selected for the job of personnel chief, Hagenbeck said, is that he came from a field command and stays in touch with other senior officers in the field. Done right, he said, "it's a very intuitive job. You can crunch numbers all day long, but commanders in the field know that there are a lot of nonquantifiable reasons that a soldier stays in, and that's why I'm here."

The major event making his work complex is the difficult U.S. occupation of Iraq. The Army had hoped to quickly draw down its force there, from a peak of about 160,000 a year ago to about 55,000 by last fall. Back then, the Army talked about Iraq as a "spike" in troop requirements rather than a "plateau."

But when the occupation proved more troublesome than envisioned, with dozens of daily attacks on U.S. troops and more than 800 now dead, those troop levels were revised repeatedly. The Army kept 135,000 soldiers in Iraq through this spring, but hoped to come down to about 115,000 after that.

Then, in a second wave of revisions following an upsurge in violence in April, the Pentagon decided to keep the troop level at about 135,000, and said it is planning to maintain that size force through the end of 2005. There is no more talk at the Pentagon of Iraq being a spike.

Now Hagenbeck's subordinates are combing through Army records, looking for troops and units that might have been overlooked and can be used to relieve the load on the troops in Iraq -- 20,000 of them extended beyond a year of duty there.

One major effort is a look at the Individual Ready Reserve, a generally dormant pool of about 118,000 people whose terms of active military service are over and who are not assigned to a reserve unit -- but under the law can be recalled to duty. Hagenbeck said that records are being reviewed to ensure the Army has the correct names and addresses for those people, but he said there are no plans to call up those reserves in large numbers.

"We're just kind of looking to see what do we really have out there, in the event that we need to recall them," Hagenbeck said. "If you start taking the perspective that we're in this fight for a long time, we need all the assets that we've got."

In another sign of how pressed the Army is for troops, it announced earlier this week that it will send overseas two crack units normally used to train deploying troops. Those outfits -- the 11th Armored Cavalry Regiment of Fort Irwin, Calif., and the 1st Battalion of the 509th Parachute Infantry of Fort Polk, La. -- play the role of the "Opfor," or enemy force, at the Army's two premier training centers in the United States. At the moment, Hagenbeck said, the key to the Army's personnel situation is the value that soldiers see in their service. He noted that the reenlistment rate for soldiers who have been deployed on a combat tour is higher than for those who have not.

"The soldiers are very proud of what they've done; they think they've made a difference," he said.

He said that he would oppose reinstituting the draft for a number of reasons, but the one he feels most strongly about is that the Army needs to maintain high levels of education, training and discipline in its soldiers. "Having lived through that, the quality of troops from when I signed up in 1971 can't compare to today," he said.

Today's troops are different in other ways than when he joined the Army out of West Point 33 years ago. "When I came in, you were faced with a pretty static environment," Hagenbeck said. "You knew basically where you were going to fight if the balloon went up."

Now, he said, soldiers understand that in any given set of a few years, "they are going to be deployed somewhere, sometime."

Lt. Gen. Franklin L. Hagenbeck, at a briefing while deputy commander of U.S. operations in Afghanistan, said his job as head of Army personnel is the hardest he has had.