MARCH AIR RESERVE BASE, Calif. — Working in an air-conditioned trailer nicknamed the Dumpster, Predator pilots peer into Iraq through a bank of computers, operating by remote-control the drone via keyboard and chat software — and occasionally unleashing missiles on enemy fighters.

When their eight-hour shifts are done, they merge onto the highway and blend into the Southern California suburbs.

For the growing number of Air National Guard troops involved in unmanned combat missions, it can be a whiplashing daily transition, and one that is taking a toll on a few of them.

"When pilots finish their job sitting in the ground control station, they climb out of that thing, hop in their car and then they drive home, and they have just been basically at war," said Col. Albert K. Aimar, commander of the 163rd Reconnaissance Wing here.

"The psychological stress, the emotions they're dealing with from fighting a war and then going home and seeing your kids and playing soccer or jumping in the pool with them, there are tremendous emotional issues," he said.

A Predator's video cameras are powerful enough to allow an operator to distinguish between a man and a woman, and between different weapons on the ground, unit commanders say.

Aimar, a weapons system operator on F-4 fighters in the 1970s, said flying unmanned Predator drones in combat can weigh on a pilot and on the sensor operators who control cameras and weapons systems.

"When you come in (with a fighter) at 500-600 mph, drop a 500-pound bomb and then fly away, you don't see what happens," said Aimar, who holds a bachelor's degree in psychology. "Now you watch it all the way to impact, and I mean it's very vivid, it's right there and personal. So it does stay in people's minds for a long time."

The 163rd has called in a full-time chaplain and has enlisted the services of psychologists and psychiatrists to help ease the mental strain from this remote-controlled fighting, Aimar said.

Several pilots said mentally walling off their military life from civilian life was key.

"I think you have to compartmentalize," Lenahan said. "A year ago I was going through a divorce, and coming in to do this job, I had to leave that at home."

Still, each said the job, which often involves protecting U.S. troops, was a great source of pride.

A veteran F-16 pilot, Col. Chris Chambliss flew missions and bombed targets during Operations Northern Watch and Southern Watch in Iraq in the 1990s. That experience prepared him for his current job as a Predator pilot, he said.

"You do stick around and see the aftermath of what you did, and that does personalize the fight," Chambliss said. "You have a pretty good optical picture of the individuals on the ground. ... The images can be pretty graphic, pretty vivid, and those are the things we try to offset. We know that some folks have, in some cases, problems."

Chambliss emphasized that the number of such cases is very small compared to the number of people involved in Predator operations, and the number of hours the planes are being flown.

Over its first year of flying Predator missions, Col. Gregg Davies, commander of the 214th Reconnaissance Group in zTucson, Ariz., said he knew of no member of his team who had experienced any "trauma" from "engaging enemy through the Predator."

Himself a Predator pilot, Davies said he has found the work rewarding. The Arizona Air Guard unit flies Predators in both the Iraq and Afghanistan theaters.

It has often provided overflights for American convoys, and its personnel have seen roadside bombers planting explosives.

"If we can have an effect there where we can take people out, that's a real plus in terms of saving American lives," he said by telephone.

"Our folks look at it as they're in the fight, they're saving lives. They don't feel too bad about that."