FORT BENNING, GA., AUG. 29 -- Wayne T. Hewlett of Landover, Md., a 17-year-old who grew up in Washington-area ghettos polluted by crime and drugs, was only 3 years old in 1972 when President Richard M. Nixon carved out an unexpectedly bright future for him. Hewlett is now living that future enthusiastically as an apprentice infantryman at this sprawling Army base outside Columbus.

He successfully completed his seven-week basic training course today.

Fifteen years ago, Nixon changed the lives of Hewlett and many other American teen-agers by abandoning the draft and telling the Army, Navy, Air Force and Marine Corps to find ways to attract volunteers. It was a monumental gamble that appears to be paying off.

Weeks of Washington Post interviews with young trainees here, with no drill sergeant or officer in earshot, confirms what senior officers are claiming -- that the All Volunteer Force has created a new generation of recruits who want to be in the Army and want to do well.

Hewlett is one of several Washington-area recruits who typify this new generation of American soldier. The youngest 17-year-old in Delta Company and the recruit selected to lead his platoon for most of basic training, Hewlett came from a divorced family, living sometimes in the Washington area with his mother and other times in Durham, N.C., with his father, a former Army sergeant.

"It was rough growing up," he said of life in Northeast Washington and Seat Pleasant, Md. "Crime, drugs. Very rough. There was one point in high school where I didn't care. My father told me, 'You're going to have to make it into the service. You're going to be nothing in life unless you straighten up.'

"And here I am in the Army. I joined to get away from home, for adventure, to get money for college. I can't believe basic is nearly over. In high school, I always wanted to be a leader but was scared of it. Now I've been platoon guide {leader}. It's the biggest thing I've ever done. It's me. It's my passage to manhood. I'm going airborne {into paratrooper training}."

Nixon created an All Volunteer Force in hopes of cooling the national rage over the Vietnam war, fueled in part by the perception that a disproportionate number of poor and blacks had been sent to die there under the draft he inherited.

The Vietnam backlash by 1972 also was undercutting the traditional concept that serving in the U.S. military was honorable. Relying on volunteers in the poisoned environment of the time, critics warned, would leave the military services short of the men they needed to fight a war. For a while, it appeared that the critics were right as congressional investigations revealed one fraud after another as military recruiters desperately tried to make quotas.

The U.S. Army in Europe was demoralized in the early 1970s. Drug rings terrorized young soldiers and occasionally carried out gangland-style murders. There was racial violence in the Army, fraggings (killings or attempted killings) of officers, fear and polarization within the barracks. The noncommissioned-officer corps of sergeants, the Army's backbone, was shattered.

Gen. William C. Westmoreland, who went from Vietnam field commander to Army chief of staff in the turbulent 1970s, despaired to friends that he was not sure he could save the Army as an institution.

Congress supported the switch to the All Volunteer Force, despite deep doubts, because the draft had become so unpopular. Nixon and his defense secretary, Melvin R. Laird, capitalized on the lawmakers' desire to see the idea succeed by pushing through military pay raises.Incentive in the Bank

A greater incentive than Army starting pay for Hewlett and the thousands of other high school graduates joining the Army today is the amount of money they can put away for college by doing a four-year hitch in a combat branch like the infantry. Hewlett and his comrades-in-arms can end up with $25,200 in the bank for college after four years of Army service. The Army and Veterans Administration will contribute $24,000 of that total; the soldier $1,200.

Army leaders are inclined to call the generation of soldiers they lead as the best ever. Gen. John A. Wickham Jr., recently departed Army chief, did so repeatedly in talking about today's soldier. But the officer in charge of training the new breed here on the ground goes beyond the headquarters huzzahs and tells why he believes the Army has completed a 180-degree turn that "the country hasn't been told about."

"It's a different environment," said Col. Richard S. Siegfried, whose job as commander of the U.S. Army Training Center here is to turn 30,000 teen-agers a year into "hard-bellied infantrymen."

"These guys in training are not here because some judge sent them here by saying you can't make it in society, so I'm going to let the Army square you away. They're not here because they're trying to get away from mom and dad; not because they can't find a job. They volunteered to be here. They want to succeed. If they aren't trying hard to succeed, they will be punished by being sent home, not the other way around. These guys want to do well; want to become part of the team. That all by itself creates an atmosphere that you see all around you."

What has made the difference? "National pride," Siegfried asserted as he walked around the office here occupied by Gen. George S. Patton while he was at Benning developing World War II tactics. "A lot of it came out of Washington, D.C. -- Ronald Reagan. There's a renaissance -- a new 'Let's come to grips with Vietnam, finally,' a new willingness to say, 'Hey, it's an honorable thing to be a service man or woman.' It's an upsurge the country doesn't know about."

There are streaks in a predominantly bright picture of the new Army-in-the-making here. A few teen-agers found Army life so intolerable they tried to commit suicide. And one 17-year-old National Guardsman almost died after heat felled him during training in the merciless August sun beating down on the Georgia pinelands.

Also, a relatively few trainees admit to having been arrested for burglary and other offenses while still juveniles. "My probation officer sent me here," one said. But these recruits seem to be the exceptions. There is also some black-white tension, but not nearly as much as in the 1970s.

The Post focused for the past three weeks on the 200-member Delta Company of the 5th Battalion of the 1st Infantry Brigade. The Army imposed no restrictions on interviewing trainees. The young recruits in scores of interviews said that they see joining the military as a step up; that they want to do well; that they believe the profession of arms is an honorable one. For them, Vietnam is as remote as World War I is to their parents.

John Brooks, 19, of College Park, Md., like Hewlett, said he believed the Army could make him live up to its recruiting slogan, "Be all you can be." He said during an interview on the Sand Hill training complex that he broke off his studies at the University of Maryland and "joined the Army to get disciplined. I had no incentive. My grades were slipping. I wanted discipline, and I wanted to to save money so I would not have to borrow to finish college. I'm glad I joined."

Dallas Henderson, 18, a graduate of Fairfax County's Lake Braddock High School, said that even after 17-hour days of pushups, crawling under barbed wire, running four miles, being yelled at by drill sergeants and sleeping on the ground where Georgia's red fire ants bite all night long, he was still glad he signed up for the infantry because it would lead him where he wanted to go in life.

"I joined most of all for the college," he said.

His father, a carpenter, and his mother, a legal secretary, are divorced. "I didn't want to ask them for college money. I get a little homesick once in a while," Henderson continued. "So I called my mother. She sent me back a whole mess of pictures of my friends right away. She's great. She's more like a sister to me than a mother."

Barry Williams, 21, of Dallas, is among the blacks interviewed who said he found the Army a less prejudiced employer than the civilian employers he had been working for, most recently as a $4.10-an-hour dishwasher in a restaurant. "In the Army," he said, "I learned if you give respect, you get respect."Encouraging Racial Integration

Blacks still tend to stick together in off hours and in the dining hall. Drill sergeants, perhaps mindful of Vietnam-era racial polarization, often integrate the groupings. "Drill Sgt. Rodriquez will come over when a bunch of us are sitting together," said Hewlett, "and say, 'We need to put a little vanilla ice cream in with all this chocolate sauce."

The unhappiest man in Delta Company turned out to be an 18-year-old from Michigan who joined the Army largely to get away from his financial and personal troubles. He found basic training so intolerable that he sneaked into the barracks shower and swallowed a bottle of pain pills in an attempt to kill himself. A fellow recruit found him just in time to enable the base hospital to save him.

"I didn't have the motivation or the strength for Army life," the distressed youth said in an interview conducted after he had recovered. "It was hard for me to do 42 pushups. They picked on me," he said of his platoon mates who were sometimes penalized for his flagging performance. "But they picked on me worse in high school. I learned something about myself; about my vulnerabilities. I'm not angry at the Army."

At times, the young troops in training cannot contain their enthusiasm. After crawling up a hill in the August heat, shooting down targets with his M16 rifle and hurling grenades until he took the hill, one sweaty recruit turned to his drill sergeant and yelled, "Sergeant! I love this stuff" -- or something of that nature.

Stephen Granoth, 17, of East Morris, Conn., was gung-ho about Army infantry tactics, too, since he was old enough to carry a plastic rifle. He joined the National Guard as soon as he was old enough. He carried 60 pounds of rocks around in his knapsack on streets near his home to harden himself for the basic infantry training at Benning this summer.

The heat made Granoth feel woozy early one August training day but he kept at it. He passed out marching back toward the barracks after his day in the sun. Doctors who treated him at the base hospital said Granoth's temperature passed 108 degrees, usually fatal. Granoth broke out of his coma but has not yet regained speech.

The August heat of Fort Benning has to be felt to be believed. The sun feels as if it is penetrating deep into your head. The heat boils off the tar in the pines, weighting the air to the point of near suffocation. The sand underfoot feels hotter than melting city pavement. Although Granoth, a member of Charlie Company of the 9th Battalion, has been the most serious heat casualty so far, dozens of other trainees have passed out. Six members from Delta Company were hospitalized for heat injuries after they had been ordered to do punitive exercises earlier this month.

Siegfried said that as the training commander "I have to believe accidents are bolts of lightning, that heat injuries can and must be avoided." A few drill sergeants have been reprimanded for not being attentive enough to the danger of overheating trainees. An investigation of the Granoth case is under way.

Drill sergeants say they must walk the fine line between training soldiers to fight in places as hot as Nicaragua while not overheating a group of American teen-agers, many of whom never experienced hot summers.

Weeks of observation did not find Army drill sergeants systematically debasing recruits in ways portrayed in such Hollywood movies as "Full Metal Jacket." They bawl out errant recruits by calling them "hero" and "yo-yo" far more often than resorting to the old standards such as "maggot" and earthier street expressions.

"I probably have a drill sergeant out there right now abusing one of my recruits, and it hurts me," Siegfried said. "But I think we're getting through. I don't want to demean people and tear them down to nothing and build them back up into something, because we could just build an Army of robots that way.

"I want to build on God-given talent. You take 50 men and try and build on each one's capabilities -- that's a very difficult leadership challenge. Tearing them all down and treating them like no-names, making them like automatons is a much simpler thing to do.

"You want a drill sergeant who makes his men say, 'He's good. I want to be like him.' All my life I've been trying to live up to my old drill sergeant, Carl Burton. He was the best man at my wedding, gave me seven bucks and loaned me his '57 Ford so I could entertain Maggie {his bride} for two days."

Sgt. 1st Class Raul Rodriguez is one of the most popular drill sergeants in Delta Company, with his immediate superiors and the trainees. He relies more on gentle humor than nose-to-nose shouting to make his points. A slow trainee is likely to hear Rodriguez tell him that "you've got a bad case of mucosis -- iron in the blood which turns to lead in butt." The ensuing laughter makes the recruit move faster.Incident Becomes a Tutorial

One morning Rodriguez "dropped" trainee Harold Hudson, 18, of Omaha, for shaking corn flakes into his mouth when he was supposed to be standing at attention. Being dropped means doing pushups for punishment. Later in the day Rodriguez turned the incident into a tutorial for the whole company, ordering "Munchies" to stand up and engage in this dialogue:

Rodriguez: "Explain to everybody, Munchies, the proper position of attention."

Munchies: "The proper position of attention is feet on the line at a 45-degree angle; legs straight, not locked; knees slightly bent; back straight; chest slightly out."

Rodriguez: "Outstanding. You could be a drill sergeant, couldn't you?"

Munchies: "No, drill sergeant."

Rodriguez: "Yes you could. Not only that, tell everybody what your IQ is."

Munchies: "About 150."

Rodriguez: "Very outstanding. You're a good man, Munchies. Now tell everybody why you got dogged out."

Munchies: "Because I ate cereal while we were in formation; while we were supposed to be at attention."

Rodriguez: "Now, was that the proper position of attention?"

Munchies: "No, drill sergeant."

Rodriguez: Thank you. Have a seat. Listen up, men; listen up. You think it's funny. But the main ingredient of a successful military unit is the discipline of its soldiers. I'm not picking on you Munchies, there, but you just give a good example, right? If you're in a combat situation, and you have to depend on the guy next to you, and instead of watching the perimeter he's munching down some cereal -- the next thing you know you've got a bayonet up your ass, and you'll want to know where your buddy was."

The typical infantry volunteer training here is a son of the working middle class. He sees himself as getting somewhere by joining the Army and often exhibits a sense of mission as he trains at the Sand Hill complex here.

Some of the old problems persist, such as the occasional insensitivity to heat problems. Also, the M16 rifle jams frequently, just as it did in Vietnam, although once again there are promises that the new version will be better.

But pride in soldiering, so hard to find in the early '70s, is indisputably back. The spirit of the new GIs was summed up by marching troops on a recent August afternoon as they chanted in cadence, "We're standing tall; we're looking good; we ought to be in Hollywood; one-two; three-four."