ALTHOUGH they have come to public attention only lately, arguments over the military utility and deterrent value of "enhanced radiation weapons" -- the neutron bomb -- have occupied the national security community for two decades. They have always been inconclusive.

Army commanders have been reluctant to procure such weapons largely because the radiation effects on which they rely would rarely kill enemy personnel instantaneously, leaving many irradiated troops capable of fighting for some period after an attack. This problem is bound to persist with the systems currently proposed. If, as some sources indicate, personnel within 200 to 300 yards would be incapacitated in a few minutes, others might receive lethal doses out to more than half a mile, although they could survive for days or weeks. The battlefield scene would deserve Herman Kahn's famous caption: "Will the living envy the dead?"

One of the greatest uncertainties concerns the likely behavior of these "walking corpses." Knowing that they face prolonged agony and certain death, would these troops lay down their arms or would they exact vengeance? The matter is especially pressing if the affected forces control nuclear weapons of their own.

Given such battlefield uncertainties, what accounts for the Army's recent shift to favor neutron weapons? Political, bureaucratic and technical factors appear to have combined. Worried about the aging nuclear components of its European arsenal, the Army was rebuffed three years ago when it sought congressional approval to modernize its tactical warheads. Influential members of the Joint Committee on Atomic Energy, prompted by experts from the Los Alamos and Livermore nuclear laboratories, withheld support, complaining that the tactical nuclear innovations were too "conventional." Politically, it was clear that the Army would have to suggest more dramatic changes.

Bureaucratically, some figures in the Army had come to fear the steady erosion of their nuclear mission. The drastic decline in nuclear-capable air defense forces had been followed by the negotiated abandonment of the Army's anti-ballistic missile (ABM) system, the service's best hope for a long-term nuclear role. There was talk in NATO and in the Mutual Balanced Force Reduction discussions of cutting the number of theater nuclear weapons in Europe. Thus, there were powerful institutional reasons for the Army to devise novel and exciting weapons to protect its claim to a nuclear mission.

Technologically, work on warheads for the ABM system had made significant progress toward enhancing various types of radiation. Weapon engineers had explored different kinds of "kill mechanisms" for use against missiles and had tinkered with ways to "finetune the output spectrum" from nuclear detonations. There was much interest in finding an alternative application for this costly and hard-won knowledge.

Furthermore, the legacy of James Schlesinger's tenure as Secretary of Defense was a heightened interest in the Pentagon and among our NATO allies in forging nuclear systems capable of discrete attacks and less wholesale destruction. Faced with these inducements and the very impressive threat of Soviet armored forces, the Army hierarchy overcame its persistent skepticism of enhanced radiation devices.

Yet this history only underscores the fact that policymakers have not addressed the vital issues. Would such weapons increase or decrease the likelihood that nuclear weapons would actually be used, raising or lowering the so-called nuclear threshhold? Would they strengthen or weaken deterrence of Soviet attack? Would they facilitate or impede negotiated restraint on the use of force in Europe and, more generally, on the nuclear arms race between the United States and the Soviet Union? In sum, would they contribute to American security? These questions defy final answers but they demand scrupulous judgment. Why the Secrecy

THE DISREPUTABLE procedure through which the weapons nearly evaded legislative and public scrutiny may prejudice one's initial view of the case. If the purpose of enhanced radiation warheads is to bolster deterrence, why were they cloaked in such secrecy? Deterrence exists in the mind of a potential adversary, not in the hidden recesses of the public works budget.

Though unaware of the original proposals, President Carter has become a party to a badly tainted procedure by urging Congress to pass the appropriations before he has completed his own review of the program's merits. He can redeem this violation of democratic process only by the most thoroughgoing and critical evaluation of the program. Carter's evident concern for the horrors of nuclear war gives hope that he will attend the problem with special care -- but that same concern may make him vulnerable to the tempting prospect of "more humane" weapons.

One can be sure that no presidential study will resolve the fundamental dilemmas posed by all tactical nuclear weapons. It may be that the deployment of neutron weapons could reinforce deterrence by persuading Moscow that NATO would use them, if necessary, repel a conventional attack. That increment of deterrence, however, is likely to be minor compared to the overwhelming influence of 7,000 U.S. nuclear weapons already deployed on the continent, weapons which the Russians have every reason to fear would be employed, not only against invaders but behind their lines.

Moreover, we must reckon with a perverse consequence of deploying enhanced radiation systems. To the very degree that the Soviets expect such weapons to be used against conventional armor, we increase Moscow's incentives to launch preemptive nuclear strikes against ur tactical forces. Russian doctrine already emphasized the likelihood that any war would go nuclear, preemptive nuclear attacks are common topics in Soviet military discourse. Thus, the price of a putative increase in deterrence by deployment of neutron bombs is further pressure on the Soviets to go first with weapons that would render meaningless any hypothetical limits on damage promised by new U.S. weapons. The net result is likely to be a reduction in the slender chances that a conflict could remain conventional long enough for diplomacy to exercise its own powers of damage-limitation.

The proposed investment in neutron warheads to fit three tactical weapons systems in Europe -- the Lance missile and both 8-inch and 155-millimeter artillery --would also divert funds from the pressing need to improve survivability for nuclear forces deployed in Europe.

If we are serious about a tactical nuclear option for NATO, the urgent requirement is to reduce the vulnerability of such weapons to the kinds of preemptive strikes the Soviets might mount. Only by concerted action on this front can we diminish the danger that nuclear weapons will be used at the very outset of a European war. Money spent on enhanced radiation weapons, which could ultimately approach $3 billion, will do nothing to meet this central weakness in the force.

Equally important is the fact that a comparable expenditure could well buy a more effective and usable conventional capability to deal with the threat of Soviet tanks. With the advent of precision-guided munitions (PGM), Soviet tanks are becoming far more vulnerable to destruction by high explosives. The neutron bomb budget could add more than 100,000 precision anti-tank weapons to the NATO arsenal. Such "smart" weapons avoid the severe operational difficulties of nuclear explosives. They do not require the same degree of centralized command and control, since they are presumably authorized to attack any Soviet tank on Western territory. And, needless to say, hundreds of PGMs can be fired without yielding the devastation of a handful of nuclear weapons.

Army studies acknowledge the trade-off between enhanced radiation weapons and PGMs, but they contend that the nuclear devices could deliver a faster shock to an attacking enemy. This might turn the tide of a conventional battle.Undoubtedly, there would be a dramatic and traumatic effect from the use of neutron warheads, but the claimed advantage highlights some other troublesome features of Army employment doctrine.

In order to achieve the desired shock treatment, the Army contemplates not discrete and singular use of neutron weapons, but barrages of dozens of such rounds. Indeed, some employment packages are said to involve well over 100 nuclear warheads. This reckless employment doctrine is scarcely a plan for selective and discriminating use.

In a setting like Germany, where average population densities exceed 650 people per square mile, the Army's ideas for using enhanced radiation weapons offer no meaningful protection to civilians in the combat zone. One hundred nuclear rounds could easily be another Hiroshima. Furthermore, knowing the approximate lethal radius of nuclear weapons, the Soviets can vary their own tactics, separating their tanks enough to prevent multiple kills even by neutron weapons. This may force NATO to target each tank individually, if so, conventional PGMs will clearly be more cost-effective than nuclear devices.

All of these contingencies reveal the difficulty of calculating the consequences of a neutron weapons deployment.Some years ago, when pressed in the Senate Armed Services Committee to estimate collateral damages and casualties from using a portion of its tactical nuclear force, Army witnesses confessed their inability to do so. The same confession is in order today. The variables are simply too numerous -- and too variable. The recommended force rests more on guesswork than calculation. If one doubts that assertion, let him consider the conclusion of the Army's attempt last year to treat the matter systematically. With the shift to enhanced radiation weapons and substantial adjustments in employment doctrine, the authors found that the ideal number of weapons to deploy in Europe was the number currently deployed there. Sic semper status quo. Stoking the Arms Race

AS THE PRESIDENT deliberates on this subject, his commitment to arms control will be very much at stake. While it is possible that the Soviets have been pursuing enhanced radiation techniques, it is certain that they will do so if the United States goes forward with testing and production of neutron weapons. Every experience to date indicates that Moscow's military authorities will insist on retaining the option to match the United States technologically.

The real choice confronting the President, then, may be whether he prefers a neutron bomb or a comprehensive ban on nuclear tests, with all that it portends for the effort to curb proliferation and to curtail the Soviet-American strategic competition. Coinciding with U.S. movement toward the cruise missile, projected improvements in the capacity of U.S. missiles to strike Soviet missile silos and the general malaise of detente, the neutron bomb controversy inevitably creates the impression that the technological arms race is continuing unabated. That is not the objective to which the Carter administration proclaims its dedication.

To be sure, the Soviet Union shares responsibility for provoking these new developments in the technological competition. Moscow's introduction of mobile SS-20 missiles to cover targets in Western Europe has triggered much alarm there and allies are anxiously asking what the United States proposes to do to meet the rising Soviet threat. The steady growth in Russian armor forces has created an imbalance that demands correction or countermeasures. It may even be that some members of the administration hope to play the neutron bomb option as a bargaining chip to elicit cutbacks in the number of Soviet armored divisions.

Out of this commotion some good may emerge. Close study of the Army's proposals may persuade the President more vividly than anything else that plans to use tactical nuclear weapons in Europe are a snare and a delusion. He may well discover that the most refined nuclear weapons cannot relieve the defects of the schemes to employ them. The President could well conclude, as other have, that NATO cannot reasonably expect to counter a Soviet conventional threat except by adequate conventional forces of its own. And he may well perceive the truth too long ignored by all of us, namely, that the only proper function of tactical nuclear weapons is to deter the use of similar weapons by the other side. If the neutron bomb debate leads Jimmy Carter to these essential insights, it will have made its contribution to national security. CAPTION: Picture, To operate in a combat zone after nuclear weapons are used, NATO troops would have to wear anti-contamination suits and masks, Topics photo by Mark Ellidge; Illustration, no caption, Newsweek drawing by[WORDS ILLEGIBLE]