Young men in fatigues looking for comrades in the Beirut rubble. Wives and mothers waiting at home or in drafty hangers for loved ones from Grenada. If the recent images from the Middle East and the Caribbean have shown nothing else, it is that the price of military deterrence - and sometimes the cost of its failure - is people. They may get overlooked in the debate about Pentagon budgets, fancy new weapons, and strategic interests. But the soldiers, sailors, marines, and airmen - the ones at outposts around the world, the ones with Purple Hearts pinned to their GI hospital bathrobes - are still the core of this country's defense.
Ten years ago, on the day a formal cease-fire was signed in Vietnam, the United States ended the draft. In the wake of an unpopular and divisive war, the nation turned inward and began scaling back its military from about 3.5 million in uniform to slightly more than 2 million today. At the same time, the baby boom was reaching military age, swelling the numbers of potential enlistees. Thus was born the all-volunteer force (AVF). It raised questions about a citizen's responsibility to country. And it was a somewhat unique experiment for the age: Almost all of America's allies - and its potential adversaries - oblige their young men to some military training and service.
How have things gone since the draft ended? How have the armed services - especially the United States Army - turned out a decade later? Speaking to midshipmen and guests at the US Naval Academy recently, Defense Secretary Caspar W. Weinberger declared that ''the all-volunteer force has not only been a success, but a huge success.'' He ad-libbed that he was dropping the term and ordering everybody to call it just ''the armed forces.''
There is no doubt that over the past few years remarkable changes have occurred in military manpower. The young person in uniform is typically better educated than his civilian peers. About 74 percent of 18- to 23-year-old Americans have graduated from high school; 91 percent of those now entering the military have, up from just 68 percent three years ago. More than 40 percent score above average on the Armed Forces Qualification Test.
Yet many recruits have to wait in line before swearing to defend their country. For three years running, all of the services have met their recruiting goals well before the end of the fiscal year and had to turn away applicants. Records also are being set in the number of service people reenlisting - from a low of 18 percent just four years ago to an historical high of 26 percent today. And today's GI is less likely to have disciplinary problems.
In part, these trends reflect a change in public attitude that goes beyond the recent fervor over Grenada. ''It's all right to be in the military again,'' says Marine Corps Brig. Gen. Carl Mundy. ''It's all right to be patriotic again.''
In describing today's young GI, the pronoun ''he'' must be used generically, for the number of women in uniform has increased more than fourfold over the past decade - from less than 2 percent to nearly 10 percent of the total, more than any other country.
Many barriers to women have been broken. The percentage of military women in ''nontraditional'' jobs has risen from less than 10 percent to 45 percent. This includes communications and intelligence, operation and repair of heavy equipment, and specialists in some combat-related jobs like chemical weaponry. The Navy now has more than 3,000 women serving on ships and this is expected to grow to more than 5,000 in the next few years. Several months ago, the first all-female crew flew an Air Force transport plane to Europe. The event was greeted with not much more than mild interest.
''Women are not simply an afterthought or temporary source of personnel we used just to get us through tough recruiting times,'' says Lawrence Korb, assistant secretary of defense for manpower, installations, and logistics. ''They are an integral part of the force, they are doing well, and they are here to stay.''
But according to many experts - military as well as civilian - all is not sweetness and light with the AVF. There are major problems remaining and even larger ones looming on the horizon.
The most talked about has to do with the ''youth cohort,'' the group of young men from which new recruits are drawn. Because the baby boom is tailing off, the number of 18 year-olds will drop 22 percent over the next decade. And as unemployment continues to fall, fewer young men will be inclined to join the military for want of another job. ''Our risk is greatest from a very vigorous economic recovery,'' said Gary Nelson, a defense analyst and former Pentagon official. ''That could have a very significant effect on recruiting.''
Because they are volunteers, some one-third of all first-term recruits leave the service before the end of their initial enlistment. ''Anyone who can get a better paying job by getting out feels stupid if he doesn't,'' says Charles Moskos, Northwestern University sociologist and a well-known expert on military manpower.
He and other experts also worry about the effect of the AVF on unit cohesion, on America's ability to mobilize quickly, and on other less tangible but very important parts of military effectiveness. Since the end of the draft, pay and benefits for first-term enlisted men and women have risen dramatically. This means that many now are married, have not developed the bonds of comradeship that comes with life in the barracks, and consider their work as little more than a 9-to-5 job. Many ask, what effect will this have in a national emergency? While new recruits are more likely to have a high school diploma these days, there are other indications of declining quality of armed forces personnel. For example, the number of enlisted men and women with at least some college education has dropped from nearly one-fourth of the total during the height of the Vietnam war to nearly zero. Before the AVF was begun, more than half of all reserve personnel had been to college; today, the number is less than 5 percent.
In the Army, it is those soldiers of lesser ability who are more likely to reenlist.
''At the moment, we have 125,000 too few educated, upper mental category soldiers, and 125,000 too many poorly educated, low-scoring youngsters,'' says Gen. Maxwell Thurman, the Army's vice-chief of staff.
This collides with the growing need - prompted by the services' rush to buy hundreds of new high-technology weapons - for men and women of exceptional abilities. At a recent conference on the AVF at Annapolis, retired Gen. William DePuy, former chief of Army training, warned that very little is known about how well soldiers perform on the battlefield with these weapons. In the few instances where tests have been run, the capability of such weapons systems is much lower than expected when human performance is included. ''The Army needs more quality than it has on board, more than it is now recruiting, more than it can get under current policy or current budgets,'' General DePuy said.
Another contentious aspect of the AVF is the large number of minority men and women now serving. Blacks comprise about 12 percent of the US population, and made up the same portion of the military 10 years ago. But they now are 20 percent of the armed forces, and more than 30 percent of the Army's enlisted men are black. That figure rises to 40 percent for the Army when other minorities are added in. About one-third of those in billets most likely to see combat are nonwhite, and some fighting units are predominately black.
From all indications, this trend is likely to continue. Since the end of the draft, the portion of soldiers who reenlist and are black has doubled to nearly 40 percent.
''I cannot see how the public could allow the United States to go into action where anything approaching 50 percent of the casualties would be minorities,'' warns John Kester, a former manpower official with the Army Department. ''What happens when we start deploying troops like that and the body bags come back in the same proportion?''
''What we have right now is an Army of the poor being paid to protect society for the comfortable,'' he says. ''With respect to the danger and inconvenience of military service, the middle class does not pay its dues. . . . Conscription may appear existentially unfair on an individual basis; but the AVF is class-based discrimination.''
Others argue that with the major pay increases granted to the armed forces over the past few years, officers and career enlisted personnel (who make up the majority in uniform) now are very much middle class. It is possible for a young enlisted married couple - not long out of high school - to earn $30,000 in pay and benefits.
It is highly unlikely that Congress will seriously consider a return to the draft as long as recruiting and retention do not drop sharply and as long as the US remains free from all-out war. A Democratic presidential contender, Sen. Ernest F. Hollings of South Carolina, favors conscription. But only a handful of lawmakers agree with him.
Registration for conscription has been quite successful since former President Carter reinstated it three years ago. All but a few young men sign up as required, and there are very few critics among military manpower experts. One notable critic is Martin Anderson, former domestic adviser to President Reagan and a leading architect of the AVF. He warns that the current registration program adds to official complacency about manpower needs and masks the need for a better reserve force and faster mobilization in the event of war.
Even with draft registration, it still would take months to raise a substantial Army, says Dr. Anderson. And he points to congressional studies showing that many, if not most, of the draft-qualified men have moved since registering and have not reported their new address to the Selective Service System.
Others predict that Congress could exacerbate the situation. The public consensus for increased defense spending has largely withered, according to most polls. Concerns about the federal deficit are growing. And yet, lawmakers already have committed themselves to most of the expensive weapons systems sought by the Reagan administration. That leaves personnel costs as a likely target for cuts in the defense budget.
''Reductions in procurement do not result in large outlay savings for several years until new weapons are actually manufactured,'' says Robert Hale, the Congressional Budget Office's assistant director for national security and international affairs. ''Manpower cuts may be much more likely because they produce quick reductions in outlays, and hence in the deficit.''
Some have suggested universal national service as a way of broadening the base for military manpower. But this raises constitutional questions about involuntary servitude. Congress may have the right to raise and maintain an army , it is argued, but it cannot force people to repair roads or work in hospitals. The House of Representatives last week killed a bill that would have created a commission to consider, among other things, a comprehensive national service program.
A return to old-style conscription at relatively low pay is an unfair form of taxation, critics say, shifting the cost of military service from society as a whole to the individual in uniform. And since the armed services still need less than half the available and qualified young men (and a far smaller portion if women are included), a draft still might be viewed as unfair and class-based.
One of the more intriguing alternatives is offered by Northwestern's Professor Moskos, a former enlisted man who spends much time with troops in the field.
He says there should be ''citizen soldiers'' and ''professional soldiers.'' Under this model, citizen soldiers would volunteer for two years' service in combat arms and other low-technology jobs at relatively low pay. In return, he or she would be eligible for a generous GI Bill program of education benefits. Another type of citizen soldier could receive a lower education bonus in return for five months of active-duty training and five years in a reserve unit.
Moskos's professional soldier would enlist for a minimum of three years in return for today's relatively generous compensation, then receive significant pay and benefits increases for reenlisting. GI Bill education benefits could be transferred to family members, and he or she might be allowed a sabbatical for professional civilian training in a speciality.