They marched like soldiers. They talked like soldiers. They ate, slept and dressed like soldiers. But for 20 minutes one day last week, as a high-ranking Army officer inspected the group of about 30 young men and women -- from their navy blue caps to their shiny black shoes -- the occasional giggle, wilting postures and drooping eyelids gave them away.

First and foremost, these were summer campers.

About 30 Arlington high school students enrolled in the Air Force Junior Reserve Officer's Training Corps spent the past week at Fort A.P. Hill in Caroline County, Va., a 600-square-mile Army training post, learning about leadership, discipline and teamwork from training instructors.

Many cadets said they went to Fort A.P. Hill to have fun. For others, it meant little more than a grade. But for all the cadets, it was the closest they could get to know the military on their own terms, with no obligation to join at the end of high school.

"It's a military-oriented summer camp to help them work together as a team," said John Clark, a retired Air Force master sergeant who instructs the cadets during the academic year. "They're learning as much or more as the people who have to be here."

About 115 students from Arlington's four high schools, most between 14 and 18 years old, enrolled in the two-year JROTC program last fall. The students spent two course periods a day at the Arlington Career Center learning aviation history, navigation and other topics, and wore a uniform to school once a week. The program also offered competitive drill teams and sports.

About 90 students stuck with it, and an elite 30 got to go to Fort A.P. Hill, where instructors eyed them for their leadership ability and evaluated them daily for their participation and attitude.

Last Thursday, a few minutes before boarding a school bus to the Army post, Necola Pierce and Claudia Delgado, cadets who had been there before, told an uninitiated cadet what it was going to be like.

"Dirt in your hair, dirt down your back," Pierce said.

"Losing 20 pounds every day. Sweat pouring all over your body. People yelling at you," Delgado said.

"And they're not always nice," Pierce said.

So why were they going through it again? "It's fun," they said.

The cadets had a full schedule, outlined in detail in a 50-page operations directive.

On Friday at 0430 hours, the cadets emerged moaning from the barracks, did jumping jacks and other exercises, split into two squadrons, ran two miles, went on a 15-minute march, went through a formal change of command and practiced a drill.

Then breakfast.

Later that morning, the cadets donned camouflage fatiques to do battle with their levels of confidence at a military obstacle course. To get there, they rode a bus deep into the woods, past mysterious gravel offshoots that disappeared into the trees, marked by such inviting signs as "Grenade Assault Course" and "Mine Field."

On the obstacle course, cadets cheered each other as they climbed ropes, hoisted each other up a tower without steps, jumped over a swinging hurdle, walked the length of a rolling log several feet off the ground, or scrambled under barbed wire. Although cadets could refuse to do any obstacle they found objectionable, the only feat some of them refused was lunch -- highly caloric army rations offering entrees such as a square-shaped mixture of ham, chicken and egg packaged six years ago.

During the morning, when one cadet, in an attempt at humor, likened the activities to a Rambo movie, Sgt. 1st Class Steve Ortwein set the record straight. "Rambo is fun to watch, but one person in a situation like that would be a dead person. Individualism is good, but teamwork is what wins," he told the group.

After lunch, the cadets learned to rappel from a wood tower, retreated to the main flagpole for the lowering of the flag, ate dinner and played softball before lights out at 2200 hours. Still, for some lucky cadets assigned to two-hour night watches, the evening was just beginning.

On Saturday the cadets are awakened at 0400 hours because they had not been very good at getting up at 0430 the day before.

The cadets did not fit any particular type. Some were large, some were short. Nine were women. As a group, they represented about 10 nationalities, including Cambodia, Laos and Guatemala. Some plan to go to college after graduation.

Joanne Marshall said she entered the two-year JROTC course because she grew up in a military family and plans to join a branch of the service. Anthony Gray said he enrolled because he felt restless and had a negative attitude about school.

Others were immigrants who saw the military as an opportunity. Juan Miranda, who came to the United States from El Salvador six years ago, said he feels he owes the United States for restoring his freedom.

"In El Salvador, when I was 10 years old, I saw people dead on the side of the road. I saw cows eating people meat," he said. "You didn't have the right to say you didn't want to go into the military.

"Here, you have your choice," he said. "I think I can use my American citizenship to do good."

If the cadets had anything in common, it was a feeling that they and the program are misunderstood. Many said that it took friends and families a while to get used to the idea. "They think it's embarrassing to wear a uniform to school. But after a while they get used to it. It seems you get more respect," Delgado said.

"A lot of people don't understand. They think we're some sort of pipeline for sending people into the military," said Kenneth Daly, director of the 316 Air Force JROTC programs worldwide. "What we need today, more than the military, is an informed citizenry. The people that don't go into the military from ROTC will have an understanding of armed forces and what it's like."

The talk of military cutbacks and the crisis in Kuwait have not deterred many cadets from considering a military life. "It might help out, in a way, if there is a war. Hopefully there isn't, but it might help. Now they might need more people," James Lawrence said.

Lawrence said he joined JROTC because he always wanted to be a pilot. "The first year I went into {JROTC}, I didn't know much about it. I didn't do well," he said. Then "I worked real hard, and they saw I was good. They gave me the chance to succeed and I took it."