Whether the United States or the Soviet Union is ahead in strategic nuclear weapons is an argument anyone can engage in but no one can definitively win.

This is because there is something for everybody in the new nuclear math, the numbers the Pentagon issues each January on how much holocaust the two superpowers have aimed at each other.

Hawks, in demanding more weapons, can cite the Soviet lead in sheer tonnage of H-bombs. Doves, in calling for a halt to the arms race, can cite the American lead in the numbers of bombs and warheads. There the argument is joined.

The numbers used in those arguments show that at a minimum, both sides have far more than they need for inflicting "unacceptable" damage on the other after absorbing a first strike. This is the level that has long been accepted as the basis for mutual deterrence -- the doctrine that has kept the two nuclear superpowers from blowing each other up.

During the 1960s former Defense Secretary Robert S. McNamara repeatedly tried to quantify how much nuclear might was enough to make the policy of mutual deterrence work. Soviet leaders, McNamara judged, would be deterred from pushing their button if the United States had enough bombs to destroy "one-fifth to one-fourth" of the Soviet population and "one-half of her industrial capacity" after the United States had absorbed a first strike.

The destructive capability of the American nuclear arsenal, and that of the Russians' arsenal, has gone far beyond that scale of retaliatory strength.

The United States has 8,500 H-bombs available to dump on the Soviet Union's 60 major military targets and 200 cities. The Soviet Union has 4,000 bombs to drop on corresponding targets in the United States.

Each superpower has built three delivery systems for those bombs: long-range bombers. Iand-based intercontinental missiles and missile-firing submarines. This three-pronged force is called a "triad" in the argot of war plannera.

Pentagon officials defend the size of the American warhead and bomb stockpile on grounds that no one knows how many would be destroyed in a surprise attack, miss their targets or be knocked down by Soviet defenses. They have no ready answer to the question of how much is enough in providing security in numbers. Less than one-fourth of the U.S. force of 41 nuclear missile-armed submarines could deliver 1,600 H-bombs of 50 kilotons each in a second strike.

The warhead advantage on the American side is due, primarily, to the technology of piggybacking several H-bombs on one missile -- the socalled MIRV (Multiple Independently Targetable Re-Entry Vehicle). MIRV, for example, has multiplied fourteen-fold the number of H-bombs one missile tube on a Poseidon sub could fire at the Soviet Union.

The Soviet Union, which in the early days of the missile race opted for giant missiles with H-bombs up front, is now following the U.S. lead and MIRVing its missiles.

The Joint Chiefs of Staff warn that the United States dare not let the Soviet Union push ahead in both quantity and quality of strategic nuclear weaponry.

Nonetheless, Soviet defense planners feel obliged to keep up with what they conceive to be a rough equivalency with the United States.This is the underlying dynamic of the nuclear arms race.

The Brookings Institution estimates that when the U.S. and Soviet megatonnage is put on a comparable basis --ets control 5.3 billion tons of explosive power as compared with 4.2 billion tons for the United States.

Accuracy is the crucial multiplier in the new nuclear math. The megatons that count are those that arrive on target. In nuclear math the chances of destroying a target are cubed by the factor of accuracy. A Minuteman missile with a 1.5-megaton warhead hitting a half mile from its target has the same chance of destroying a missile silo as a 12-megaton weapon exploding a mile from its target.

The United States has opted for higher accuracy and less megatonnage in its warheads. Of the 1,054 ICBMs listed in the U.S. inventory, 54 are Titan II liquid-fueled missiles with nine-megaton warheads and the rest are ICBMs from the Minuteman family, each carrying smaller but more accurately propelled warheads.

The margin of accuracy for the Titan II is one mile; for the Minuteman III, one-quarter mile.

On the nuclear evolution scale, the United States moved from the nine-megaton Titan II to the submarine-launched Poseidon, which can fire clusters of 10 warheads of 50 kilotons each within a margin of accuracy of fewer than four city blocks.

The latest technology wrinkle in upgrading the accuracy of missile systems is MARV (Maneuverable Re-Entry Vehicle) -- son of MIRV -- each of whose warheads is guided by an electronic "brain" that locks the bomb onto a target, even though it may be thousands of miles away. MIRV warheads ride like passengers on a bus and are dropped off along the trip at a point from which they will fly, directed by gravity and the momentum of the "bus."

MARV's birth was greeted with critical comments from some arms controllers who see the "smart" H-bomb warhead as a major leap into the irreversible momentum of first-strike technology.

In overall numbers, the U.S.-Soviet missile balance for the three major systems of the weapons triad is as follows:

For land-based intercontinental ballistic missiles (ICBMs): U.S. 1,054 --U.S.S.R. 1,450; submarine missiles: U.S. 656 -- U.S.S.R. 880; long-range bombers: U.S. 418 -- U.S.S.R. 210.

Although these totals seem to reflect a Soviet superiority in missiles --2,540 to 2,128 -- there is an offsetting factor in the 2-to-1 U.S. lead in warheads. Missiles merely propel. Warheads explode.

Here is how the weapons experts assess the two powers from the standpoint of each major weapons system:

Long-range bombers: The U.S. edge here is wider than the numbers make it appear. A key to how much a bomber can carry and how far it can fly is the number of tankers available to refuel it in flight. The U.S. tanker fleet is far superior to the Russian fleet.

Also, the United States already has a new strategic bomber flying, the Air Force B-1, while the Backfire is the only Soviet bomber in production. Backfire is a medium bomber that U.S. military leaders consider capable of strategic bombing. The U.S. Joint Chiefs of Staff reported this year that the Soviets may build a new long-range bomber but acknowledge that it could not become operational until the early 1980s.

Land-based ICBMs: The Russians hold the decisive lead in numbers of missiles and deliverable megatonnage but this is, as pointed out, offset at the current stage of development by the accuracy of the U.S. Minuteman missile. As the Russians develop their own MIRV technology, however, their heavier-muscled missiles coupled with bigger warheads could give them more destructive power with which to strike at hardened U.S. targets.

Because of the growing vulnerability of the land-based weapons to attack, there is the question of whether they may not become obsolescent sitting ducks in a nuclear strike.

President Carter underlined the issues on the land-based weapons by offering to forgo deploying mobile landbased ICBMs, such as the Air Force's MX missile, which would be carted from silo to silo through underground tunnels, if the Soviet Union would do likewise.

Submarine-based missiles: Increasingly accurate submarine missiles already deployed by both sides, along with the advent of MARV, pose additional threats to the land-based weapons.

The Soviet Union last year started deploying its 500-foot-long Delta II nuclear-powered sub that carries 16 SSX-8 missiles, which have a range of 4,200 nautical miles.

The United States in 1979 expects to send its 560-foot-long Trident to sea. Each of these subs will carry 24 Trident missiles with a range of 4,000 nautical miles at first and 5,000 miles later.

Because of their long-range missiles, each of the sub systems -- the Delta II and the Trident -- can stick close to the safety of port while covering potential enemy targets.

A footnote in the comparison of the rival nuclear submarines is that the United States keeps about 50 per cent of its fleet at sea at all times, according to the Joint Chiefs, while the Soviet Union deploys only 11 per cent of its ships.

With so much nuclear firepower going to sea in submarines, is it safe to assume that the two superpowers are backing away from the risk of mutual incineration because each has an invulnerable retaliatory force at the ready in the ocean depths?

If the submarines armed with missiles were truly invulnerable, then one could reason that the "we-won't-if-you-won't" underpinning of deterrence is securely in place. But the constant upward spiral of technology has not let this happen.

The United States can, and does, track Soviet missile submarines with American hunter-killer subs and with an array of detection systems, including microphones on the ocean bottom. An antisubmarine-warfare plan, called "the barrier strategy," calls for ambushing and destroying Soviet subs in a war as they sail through the straits and gaps to put their missiles in range of the United States.

U.S. killer submarines have the Mark 48 torpedo, which can swin 20 miles after launch to find and destroy a sub detected by sonar listening systems. The Soviets can be presumed to be working on the same kind of weapons.

As implausible as it may sound to laymen, Soviet planners do have to worry about U.S. capability to make a coordinated first strike where hunter subs would kill their missile subs, where highly accurate MIRVs and MARVs from subs and land launchers would disable their ICBMs and bombers, and where B-52 and B-1 bombers would finish off anything left standing.

If the U.S. Navy builds its Seafarer system for communicating with its subs in the depths, Soviet worst-case strategists would have to worry more seriously about an American coordinated first strike. Today's communications methods with submarines are complicated, requiring subs to rise toward the surface during prearranged transmission periods.

Conversely, American war planners have to worry about the Soviets catching up with U.S. antisubmarine technology now that they have closed the gap on quantity.

So far, there is no evidence that the Soviets track U.S. missile submarines the way the United States does theirs. But this secure undersea force could end up being vulnerable if the Soviets adopt U.S. Navy tactics.

And so the imponderables of time numbers and national motivation make it difficult today and perhaps impossible tomorrow to answer the question: Is anybody winning?

NEXT: "Internal" negotiations.