KHE SANH, South Vietnam-Vietnamese soldiers who marched confidently and enthusiastically into Laos three long weeks ago are returning to this forward command post near Khe Sanh visibly shaken and openly questioning the operation still continuing there.

"It's another world in there," a twenty-year-old paratrooper exclaimed to his fellow support troops-who had not yet gone in-as he jumped out of an American helicopter, minutes after leaving the front.

"Last night on Hill 30 it rained rockets. The medics tried to move the wounded but for two hours no one dared move from the bunkers," the boy said nearly breathless as he laid down his dusty M-16 rifle under a bush, and grabbed a tin cup filled with water.

"Will I go back there?" a twenty-two-year-old Ranger, two days back from Laos, asked.

"If they send me I have no choice. But I've gone once. It's someone else's turn. I want to return to my woman in Saigon," the young man shouted out in Vietnamese to a passerby.

For the men who have yet to be tested on the other side of the Xe Pon River, the boundary between Vietnam and Laos in this area, the desire to fight remains unchallenged, the spirit high. Their feelings usually contrast with those of their comrades who have tasted the North Vietnamese guns first.

"I will fight until I die or until all the North Vietnamese are driven back North," twenty-year-old Nguyen Chet, a support soldier in the 49th, Artillery Battalion, remarked, making certain others around would hear his words. Chet has not yet been to Laos.

Vietnamese believe fear is a sign of weakness and seldom like to express such feelings publicly. Such, however, is not the case for those who have been into Laos, have fought, and have returned to speak of their experiences. The heavy fighting the troops have witnessed gives the veterans a right to speak of apprehensions, a right not earned by the others.

"Two of my friends died in a rocket attack. They were on the ground just next to me at the time," one paratrooper said, his head wrapped in white bandages, his eyes peering through, as he waited to be treated in a hot tent serving as an emergency hospital.

"I have fought. No more. I just want to leave here and forget the war. I'm not afraid to die, but who will care for my children?" the twenty-seven-year-old said.

"We can fight if we have enough air support," one soldier remarked, two days after he returned from Laos. "But the rains have not helped, and the American helicopters cannot defend us if the anti-aircraft fire is too strong," he added.

Under a small tent held up by pieces of bamboo cut and tied together in much the same way Vietnamese huts are constructed in the countryside, eight members of an artillery support company discussed the Laotian operation during a rest period.

"Why aren't the Americans fighting with us?" a twenty-year-old asked, sitting on the edge of the green American army cot.

"They are watching us, seeing if we really want to fight," another soldier answered.

"No, it has something to do with the Treaty of Geneva," a third soldier volunteered hesitantly.

Shortly, a thirty-eight-year-old sergeant who had been listening outside broke into the tent. The man's dark, ruddy face, hardened by the war, looked older than his age. The man, of another generation, stated authoritatively to the young troops:

"No, the Americans are not fighting in Laos because of a small group of Americans who do not support the war in the United States. They don't understand. They want all the Americans to leave Indochina," the sergeant told his men.

THE OTHER soldiers remained quiet. The sergeant stood, helmeted, with a flak jacket buckled tightly, in marked contrast to the younger, more leisurely soldiers who wore only fatigues and carried no weapons.

One Saigon University student, drafted into the army four months ago, sat in the corner of the tent listening to the sergeant. After the older man had left, the boy, grinning, responded to the other soldiers.

"What does that man know about economics and sociology? Has he been to Saigon to see what the bars are doing to the morals of Vietnamese women and children? Will killing North Vietnamese really bring us any closer to peace?" the young man asked the troops in the tent with him.

"I saw what the rockets are doing to the paratroopers. I saw what the American airplanes are doing to the North Vietnamese. It is the American economic empire that is perpetuating this war," the boy said bitterly, his eyes squinting behind black-framed glasses. Again, the other soldiers listened, saying nothing while the boy spoke.

Moments later a corporal said in a lower voice, contrasting the student who spoke before him. "Maybe if the communists would be given a small part in the government then the war would end," the twenty-three-year-old from Hue said. "The fighting has continued so long and there are so many poor," he added.

Though different opinions emerged in the conversation, a friendly atmosphere continued as the soldiers spoke in the tent. All of the soldiers were bound together by having to fight in an operation for which none felt directly responsible.

As life on these green hills, cut up by red clay roads, becomes routine for the support troops, the combat soldiers return from Laos with stories of horror and death which are eagerly consumed by all troops here. Battles are discussed as they develop from day to day.

A wicker basket held by one soldier attested to the exploits in the neighboring country, a country most Vietnamese consider to be much more inferior and more backward than their own.

"Some Laotians have died," the lieutenant added. "They run. We don't kill them. They just get in the middle of the fighting," he said, holding up his hands to disavow any responsibility.

"Me? I have done my job. I just want to stay around here now where I can sleep at night-without the sounds of rockets and bombs."

However, South Vietnamese troops are finding no respite in Khe Sanh. Since the retreat began, Khe Sanh is being rocketed daily.

( Copyright 1971, Dispatch News Service International )