WITH U.S. TROOPS, SAUDI ARABIA -- Chaplain George Hernandez walks the Marine Corps gun lines in the Saudi desert, ministering to the lonely, the homesick and the fearful.

He coaches his congregration of young gunners, corpsmen and truck drivers through the long days of sandy misery, the torments of "Dear John" letters from sweethearts back home and the persistent black anxieties of war and death.

"Chaplain, I'm talking about death -- dying," one Marine pleaded. "I might never get home."

"Son, you're not dealing with it yet," responded Hernandez, seeking to soothe his young charge. "Let's deal with today. And today, you still have red blood running through you."

Amid the choking dust, stinking latrines and bitter homesickness, American military men and women are building emotional bridges to help cope with the isolation of their distant assignments in the Saudi desert. They have forged makeshift families among colleagues who had been little more than workday acquaintances at their home bases and have turned to chaplains, corpsmen and senior noncommissioned officers as surrogate mentors.

"This is our family now," said Lance Cpl. Brian Kyle, assigned to a Marine howitzer battery on the Saudi front lines. "We've learned we need to depend on each other more. We're the only ones out here."

The readjustment has been slow and painful for many. Hernandez said his formal religious services, held under a camouflage net in the desert, are only sparsely attended. But he added, "When the bullets start flying, it will be a different issue."

For now, with heartbreak and loneliness among the most painful wounds of this military zone, Hernandez takes his pulpit to the howitzer cannons, foxholes and five-ton trucks.

"I walk the gun line. I live with them. I exercise with them," said the 36-year-old son of a Texas minister, rolling his sleeping bag one recent morning before setting out on his daily rounds in a four-wheel-drive truck.

Over the weeks, the troops have opened up to the Navy lieutenant who counsels them with examples from his own troubled teenage years.

"A lot of them come from single-parent homes, homes with alcoholism and abuse," Hernandez said. "They don't have any coping skills. The answer they find is to run away.

"All this place does is magnify the problems," he continued. "They still have marriage problems because they had marriage problems in the first place. They have sick parents and brothers and sisters dying of cancer."

After two months in the desert, 23-year-old Marine Sgt. Ronald Brockhouse said he had received only two pieces of correspondence from home -- a letter from his girlfriend saying, "You're too far away for me to wait," and a tirade from his father angry that his son in Saudi Arabia had called home collect.

"I try to give them something they can grab onto," Hernandez said. "I talk about the heat and the cold, the moisture dripping from the camouflage netting, the misery of living in field conditions. I quote from the passages saying we are hard pressed on every side, but not crushed."

And when the biblical references fail, he uses a more direct approach. "I tell them, 'This isn't going to last forever. Someday you'll go home.' "

That day, however, seems like a mirage to most of the troops.

Air Force Lt. Steve Turner is assigned to a base so secret the U.S. military is not allowed to admit it exists. Reporters are barred from visiting, and troops are forbidden to name the country where they are deployed because its government does not want to advertise its assistance to the American military.

The several hundred Air Force personnel who work at the base live in a small, enclosed compound about the size of a square city block. There are no nearby towns, and they are not permitted to leave the compound.

"Everybody is like zombies. They see no end in sight," said Turner, 26, who is worried that he will miss his scheduled February wedding. The main diversion, he said, is the beer tent, where military bartenders serve up the two-beer ration allotted each resident every night between 7:30 and 11.

For unexplained reasons, the base recently began receiving sacks and sacks of "Any Serviceman" mail, tens of thousands of letters and packages from schoolchildren, nursing homes and church groups in the United States. Now Turner is drowning in mail -- two tons a day, far more than the residents of the small base could ever answer.

Turner's morale-boosting answer, however, was to open the "Any Serviceman Store." Troops open the packages of candy, soups, soap, lip balm, batteries and other goods and arrange them on store shelves. No money changes hands; the currency at this shop is letters. Turner and his troops have sorted 40,000 letters by state and town and stacked them on the counters. For each item a serviceman or woman wants, he or she must agree to open and answer a specified number of letters.

The more expensive items that have arrived in the mail, such as radios and tape recorders, are wrapped for distribution on Christmas morning, Turner said.

Not all of the "Any Serviceman" mail has been uplifting for the lonely troops in the Middle East.

The Marine Corps' Kyle was taken aback by a letter he received from a fourth grader who asked, "What does it feel like to know you might have a grenade thrown at you that will blow your body into a million bits?"

Texas fifth grader Janeisa Brooks sent a hand-drawn Christmas card to sailors aboard the Navy destroyer USS Sampson in the Red Sea announcing, "I think this whole event is stupid. But I'm glad they sent some of the best men and women to straighten things out."

How do sailors and soldiers respond to the straightforward questions of youngsters looking for answers to a complex international crisis? "I tell them that we're like hall monitors," said a Sampson sailor. "And the Iraqis are the bad guys."

If war erupts, the Marines of Tango Battery could be among the first American troops to meet the bad guys on the sand dunes near the Kuwaiti-Saudi border.

They live under a camouflage net next to a giant green howitzer they have named "Wilbur." At night when they collect on their sandy cots and atop heavy green ammunition boxes, the conversation turns to girlfriends and wives in this all-male battery.

Hospital corpsman Arthur Tucker will celebrate his fourth wedding anniversay Christmas Day -- in the desert, without his wife. He has run out of things to tell her in his frequent letters: "It's hot, it's sandy, I love you, bye." He worries about the odd jobs he is not around to help her do at home.

The other men on the gun have darker concerns. The 12,000-mile separation from home breeds insecurity and anxiety. They have heard rumors that the Marines left at the base back home are moving in on their wives and girlfriends.

"A guy doesn't get a letter from his girl for two days and he thinks she's left him," said a senior noncommissioned officer who has heard dozens of such tales.

"The hardest thing about being away from home is the little things you miss," said a Marine gunner. "Like going to a movie or leaving the military behind you -- even if it's only for a couple of hours."

There is a lull in the conversation. Thoughts wander homeward. Flies buzz. The desert is so quiet the men can hear the pop of a metal gun barrel contracting.

Suddenly the shout of "Fire missile" crackles over the radio. The men scramble atop the howitzer, orders are shouted, munition is hoisted, the trigger rope is pulled, the air explodes with the boom of a live round. Seconds later, bright bursts illuminate the horizon.

Commanders say the military training here helps motivate their homesick troops. "They want beer and women, but they also want to pull the string on that gun," said Marine Lt. Col. Jim Sachtleben, who commands Tango and three other firing batteries on the front lines.

Each week, several hundred U.S. troops escape their hostile desert assignments and are returned to their home bases because of medical problems, routine military transfers and family emergencies. For some troops, the return home is a wrenching experience.

Army Spec. Gerald des Jardin stood on a windswept runway in eastern Saudi Arabia on a recent afternoon watching his wife, Sgt. Yvonne des Jardin, disappear into a crowd of camouflaged uniforms.

He clumsily brushed tears from his cheek as she clambered into the belly of a mammoth green C-5 transport plane. After tests showed 22-year-old Yvonne was two months pregnant, the Army ordered her home. The military, citing insufficient medical care and harsh working conditions, does not allow pregnant women to remain in Middle East assignments and has sent a few dozen home since August.

The des Jardins, both members of the same military intelligence unit, vacated their apartment and shipped their belongings to their parents' home when they were given five days' notice that their entire team was being deployed to Saudi Arabia.

For almost a month, they lived four rows away from each other in a desert tent city. While the accommodations hardly provided for marital bliss, their joint assignment helped ease the loneliness.

Now, Yvonne, who said she did not realize she was pregnant when the team left for Saudi Arabia, faces returning to a home base where she no longer has a home or a job. The Army will reassign her to a new unit.

"Part of me wants her to stay," said des Jardin, watching as the giant transport lumbered down the runway. "She's better off going; this is no place to be pregnant. But I'm going to miss her."