They go to war, they get shot at, and they see their friends die.

But members of the military say they are more likely to think twice about re-enlisting because of the consistently long work hours, not the prolonged deployments or life-threatening combat duty, a new RAND study says.

The study released Tuesday found that active duty troops who often put in longer work hours than normal -- either at a desk or in combat -- feel greater stress. And it said that as those stress levels about their work days rise, their inclination to re-enlist slips.

"The intention to re-enlist declines as the burden of work increases," said Rand defense analyst James Hosek, a key author of the study. "It was the same for deployed and nondeployed. It was the perceived increased burden to work, not where they were working."

About 40 percent of the enlisted members and half of the officers reported working longer than a normal work day more than 120 times in a year, according to the RAND study.

But that doesn't mean soldiers, sailors, airmen and marines on combat duty in Iraq or Afghanistan weren't exhausted, burned out or stressed about being away from their families and in constant danger. It instead suggested they knew it all came with the job, the study found.

"There was no running water. There were land mines. And the bathroom was in a Port-A-Potty," one service member said during a focus group discussion. "We were attacked, shot at, had to eat MREs, and the water was rationed."

Another said: "We were told constantly that we would go home next month, but we never did. This caused morale to drop a little, but you get over it."

The study found that many military service members are eager to go to war, and say the experience is exciting and meaningful, and allows them to use their training. Money is a key factor in those positive feelings, RAND said, including higher combat pay, bonuses and tax-free salaries while deployed to war zones.

"They joined because they wanted to serve their country, and deployment meets their expectations of service," Hosek said. "They had been shot at, had been in live fire engagement, had friends killed. We were just astounded and grateful that they generally had such resiliency to cope with that."

In fact, the RAND study said those who were not deployed often felt left out, particularly if others they knew went to Iraq or Afghanistan.

While stress related to frequent long work hours hurt re-enlistment, general job stress did not.

The study found that service members who experienced higher than usual stress levels overall were more likely to re-enlist. RAND suggested the military's internal sorting process -- in which personnel are assigned or promoted to positions that match their abilities -- leads members to expect the stress and be more capable of handling it.

Similarly, senior officers were less likely to say they experienced higher than usual stress than junior officers did. But that probably doesn't mean they have less stress. It more likely suggests that those at higher levels expected it and were more accustomed to handling it, the RAND study said.

"Within the military, individuals are most likely given assignments based on their commitment and performance in the military," said Hosek. "Those who are heavily committed, a good fit, and able to handle responsibility are given more tasks."

RAND used information from focus group interviews with members from all the military services, along with results from two broader surveys, conducted in March and July 2003. Service members were on combat duty in Afghanistan at that time, and they were in the initial stages of the Iraq war. A little more than 10,000 service members responded in each of the surveys.

While the Army, Navy, Air Force and Marines have struggled to meet their enlistment goals, the most recent Pentagon report shows all the services are working well toward their end-of-the-year goals for re-enlistments. As an example, the Army had re-enlisted 10,677 soldiers -- or 92 percent of its goal -- by the end of November.