When Larry Fink joined the Navy in 1970, three years before U.S. military involvement ended in Vietnam and Cambodia, the neurosurgeon fresh from training at the Mayo Clinic thought he would never have a more satisfying practice.

That hope, for a while, proved to be true. The traumas treated at Bethesda Naval Hospital were demanding. Military doctors, drafted like many young men during those years, were part of a medical corps that was constantly changing and responding to new ideas.

But by 1976, Fink began noticing what Defense Department health officials had feared would happen without a war. There were fewer doctors, a growing discrepancy between salaries in the military and the civilian sector, and a drop in morale. In another four years, Fink would bail out and begin his own practice, now in Rockville.

"I remember when I was so frustrated with things," Fink said. "I would have conversations with my colleagues and they would say: 'Stay. It'll be better by 1984, 1985. Things will work out.' "

Things have not worked out for the military medical corps.

During the past year, the system providing essentially free care to 10.2 million active and retired service personnel and their dependents has been buffeted by an unprecedented number of audits on each branch of the service documenting poor care. Allegations of negligent care by individual doctors, such as those made against Navy Cmdr. Donal M. Billig now charged with the involuntary manslaughter of five patients at Bethesda, have added to the concern.

And a Department of Defense internal survey of 20,000 military households found that military personnel believe the quality of health care in the military is worse than civilian care. That survey, released in April, showed that persons who were eligible for military care but could afford civilian care often opted for civilian.

Military health officials question whether the care they provide is worse than civilian care. What their beneficiaries are objecting to largely, they say, is a lack of continuity in scheduling and personnel that is a fact of military life.

The problems with military medicine have been blown out of proportion, the military brass say. Nonetheless, they have instituted a number of reforms aimed at eventually guaranteeing certain standards of care.

During the past several months, committees of the U.S. House and Senate have examined military health care, asking, among other questions: What went wrong?

The answer, some military doctors and former military doctors say, lies in a doctor shortage that began about 12 years ago.

Once the Vietnam War was over, the military offered few incentives for those wanting to practice medicine. Young men no longer needed a service deferment. Salaries were lower than in the private sector, and the large bureaucracy suffered from a set of built-in frustrations. Finally, peacetime medicine with its healthier population was less challenging than that which had been practiced on the battlefield.

All these factors contributed to a slowdown in the number of American doctors going into the service. In fiscal 1972, there were 13,713 doctors on active duty in the military, according to the Defense Department. Legislation was passed that year establishing medical school scholarships and the nation's first military medical school. But it would be years before those programs produced physicians.

By 1975, the number of military doctors had dropped to 11,515. It bottomed out in 1978, at 10,792.

"Doctors weren't interested at all in signing up for a job that meant having a fixed income, moving around and working for an unpopular group," Dr. William Mayer, assistant secretary of defense for health affairs, recalled recently. "Those were lean times for the services. I don't mean they were careless, but they weren't as careful as they are now in recruiting doctors."

By 1977, Defense Department health officials were reading internal surveys that showed, for the first time, no branch of the armed services had enough physicians to provide the level of health care that American military families around the world had come to expect.

By 1979, the worry was spreading beyond the Pentagon. A survey by the General Accounting Office found that nearly two-thirds of the nation's military hospitals had shut down or curtailed services because of a doctor shortage.

For some doctors, the surveys spoke of a frustration they had felt for years.

"In 1970, there was a tremendous pool of talent both from physicians and medical personnel. There was an attitude that we were all in this together and we were going to make it. By 1980, that was a distant memory," Fink said.

"And at first, you have this feeling: 'This is my organization.' You want to stick by it. You want to believe. But I never saw it getting better. More medical people left. And the patient population -- there was less of them to work on with less interesting problems."

Money also led some doctors to leave. In 1979 and 1980, a Defense Department survey showed military doctors' salaries peaked at $59,000 and civilian doctors were earning, on the average, about $70,000 a year. The department appealed to Congress for funds to boost the salaries for military doctors.

Military health officials also discovered that the number of foreign medical graduates entering the armed services was at an all-time high. In 1976, foreign medical school graduates made up 34 percent of all the new recruits, according to data from the Uniformed Services University of the Health Sciences, the military medical school. That figure jumped to 46 percent in 1977.

Foreign medical graduates in those years were scoring much lower than Americans on advanced tests that would allow them to practice specialties -- the kinds of specialties that the military needed -- and Defense officials were alarmed at relying so heavily on doctors trained outside the United States.

By 1980, Congress and the military knew they had to do something. They started with pay raises. All medical officers not undergoing internship or residencies got immediate salary boosts of $9,000 or $10,000, and those with training in certain specialties got another bonus ranging from $2,000 to $5,000.

The pay system adopted then still exists and compares favorably with civilian pay, Defense Department personnel say, when civilian costs -- such as malpractice insurance -- are figured in.

Col. Craig Llewellyn, chairman of the department of military medicine at the military medical school on the grounds of Bethesda Naval Hospital, was drawn into the Army by a scholarship and had no intention of staying. But service led to more training, including a stint researching disease in Brazil. By the time he was eligible to leave the Army, Llewellyn had served 13 years.

"When you start interviewing at that point, retirement benefits and pay just won't match up for certain specialties," said Llewellyn, a specialist in preventive medicine. "Unless you really want to leave the military early , you don't do it. You won't make more money."

Higher salaries plus the Health Professions Scholarship Program, which now supplies the Armed Forces with 70 percent of its doctors, helped alleviate the doctor shortage. This fiscal year, the Defense Department estimates that it has 13,127 physicians, about 600 fewer than in 1972 but sufficient for all but a few specialties. The percentage of foreign medical graduates in each service has dropped to no more than 10 percent.

Air Force Maj. Daniel Coleman, a pulmonary specialist and a graduate of Georgetown University Medical School, was one of the first doctors to come through the scholarship program. "It made medical school possible for me -- particularly when I was going to what was the most expensive medical school in the nation," said Coleman, now the head of the intensive care unit at Malcolm Grow Medical Center, Andrews Air Force Base.

After medical school, Coleman spent five years training at St. Elizabeth's Hospital in Boston before his assignment with the Air Force in 1982. Confident of his civilian training, he said he could not help but wonder at that time, "What am I coming into now?"

"I have been very, very impressed with what I've found," Coleman said. Content to work within the organization -- something that gives him "gentlemanly hours" although the salary is about half of what he would make in the civilian sector -- Coleman said he works with "a lot of capable people who have decided that money is not the only thing."

"There's a camaraderie here that the outside world lacks," he said. "And I think some of us are saddened -- perhaps 'resent' is too strong a word -- that only one side of military medicine is being shown . . . . I don't think anybody should sweep something under the rug but I just have to wonder if we're not taking a lot more heat than civilian hospitals for the same kinds of problems that exist there."

None of the recent studies that have been done on military medicine have compared it to private care. Officials for the Joint Commission on Accreditation of Hospitals, a private nonprofit group that surveys and accredits hospitals, says it has never compared them.

"It's hard to compare quality of care," said Don Avent, the joint commission's senior director of surveys and development. "There are few overall figures. My impression is they do as well as civilian hospitals in gaining accreditation."

Perhaps because the public perception is that civilian care is better, the Defense Department has begun a program to have civilian consultants review its indicators of care such as morbidity and mortality rates. That decision may well have stemmed from a finding by the American Medical Association that one of every five doctors in the military did not have a medical license, the most basic of standards in the civilian sector.

Pentagon officials, who recently ordered all active duty doctors and health personnel to obtain proper licenses within the next three years, say they do not believe requiring licenses will mean that their doctors will be more qualified to practice than they are now. "To say we have unlicensed physicians and therefore unqualified doctors is unfair," Pentagon health chief Mayer said.

The Defense Department has instituted other reforms. Procedures for checking applicants' credentials have been streamlined. Moonlighting has been restricted. Meetings to discuss quality assurance are being scheduled in many of the system's 168 hospitals. About a month ago, Secretary of Defense Caspar Weinberger and health affairs advisers met with hospital commanders to emphasize the need for quality care.

"What we're trying to do now is not stoutly deny any problems or say that we're the best system in the world," Mayer said. "We don't have the figures to do that . . . . What we are doing is getting the commanders to stay in the forefront of quality assurance."