The weapons balance tilts toward the East

The numbers are bad. And they're getting worse. The Warsaw Pact fields twice as many heavy conventional weapons on the central European front as NATO does. Among these are seven times as many multiple rocket launchers, almost three times as many tanks, almost twice as many antitank guns and guided missiles.

Furthermore, the Warsaw Pact is increasing its lead. Actually, it was back in 1980 that the overall conventional ratio was 2 to 1. Today, three years later, it is more like 2.2 to 1 or 2.3 to 1, says Phillip Karber, vice-president of BDM Corporation and former director of a long-term Pentagon study of the weapons balance in Europe.

Add the Soviet superiority in European theater nuclear weapons acquired over the past few years, and the picture looks bleak for NATO.

Add the rapid strides in Soviet military technology that have eroded the West's perennial qualitative lead in weapons, and the situation looks even bleaker. Deployed Soviet military technology today is not significantly inferior to that of NATO except in electronics, according to Christopher Donnelly of the British Staff College in Camberley.

For the past 38 years, deterrence of war in Europe has proved remarkably sturdy. The current trends do not undermine this stability - yet. But they could , if they continue unchecked.

''I'm not worried about deterrence now,'' declared an American officer at NATO headquarters. ''What I'm worried about is deterrence 15 years from now if the present curves continue.''

In sum, quantitative disparities in weapons are now substantially greater than ever before and are still increasing. And there comes a point when slightly superior technology can no longer hold off overwhelming numbers.

Back in the old days, the ratios were not so alarming. Moreover, the West still had strategic and theater nuclear superiority, undisputed air supremacy in Europe, and that substantial qualitative edge in conventional as well as nuclear weapons.

Under these circumstances it was inconceivable that the Warsaw Pact could muster the minimum 3 to 1 local superiority an attacker presumably needs to be confident of victory.

Then, however, came the half dozen years of American preoccupation with Vietnam, followed by a decade of reactive American aversion to things military. Materiel diverted to Indochina - and then to resupply Israel after the 1973 war - was not replaced in Europe until the late '70s. In noninflated dollars, military budgets in the US fell steadily in the 1970s - and even dropped below the 1965 pre-Vietnam level in the latter half of the decade.

By contrast, in the same period Soviet military spending and weapons production climbed steadily. Between 1965 and 1980, the Warsaw Pact moved ahead of NATO in surface-to-air missiles (SAMs), armored attack helicopters, and antitank guns and guided missiles, and it substantially increased its existing lead in tanks, armored personnel carriers, artillery, and tactical aircraft.

In these same 15 years, America's European allies showed a mixed record. The French dealt NATO a major blow by pulling out of the unified military command in 1966 - but they did reorganize their two divisions that stayed in West Germany into modern mechanized divisions. The British Army of the Rhine trimmed its size from seven to six combat brigades. The Canadians halved their strength in the European theater.

Almost all the other allied armies reduced the number of troops they had stationed on the central front. The notable exception was the West German armed forces, the Bundeswehr.

In the 1960s the Bundeswehr - aided mightily by Soviet Premier Nikita Khrushchev's threats and the Berlin crisis of 1961 - ceased being controversial domestically and laughable within the alliance. The Bundeswehr expanded its divisional assets (weapons) by 25 percent and became, simply, the best army in Europe.

In the same period, the West (to its relief) discovered that Sino-Soviet rivalry was here to stay; that up to 1 million Soviet troops would be tied down in Asia and be unavailable for European combat.

The upshot of all this was a net loss of 50,000 NATO troops between 1965 and 1980 in a period when the Warsaw Pact was adding 150,000 troops on the central front. (Half of that Warsaw Pact supplement came from Soviet forces that stayed on after invading Czechoslovakia in 1968.)

In weapons, the two alliances expanded their combined inventories on the central front in this period by 50 percent, or 31,000 major combatant systems, according to Karber's unclassified figures. But, of these, the Soviet bloc accounted for some 25,000, or 80 percent.

By far the most spectacular leap came in Soviet air power. Back in 1965 the Soviet bloc already had some thousand more tactical aircraft than NATO. But Soviet planes were inferior machines, and their mission was restricted to air defense interception over home territory.

Moreover, Western pilots had double the training time of Warsaw Pact pilots and reveled in taking the initiative in a way the rigidly ground-controlled Soviet-bloc flyers never did. The Westerners flew better aircraft, with better avionics (aviation electronics), range, payloads, loiter time, and air-to-air munitions. The much more versatile NATO multimission planes were deemed highly likely to succeed, even in deep strikes.

Then three things happened:

* The number of NATO planes dropped somewhat - partly because European squadrons were slimmed down as expensive new high-performance systems were introduced, partly because the US withdrew aircraft from Europe to fill Vietnam needs, and partly because the US withdrew even more aircraft after the loss of French air bases rather than risk overcrowding on West German bases.

* The Soviet bloc modernized what was already the densest air defense in the world (and both the Vietnam war and Mideast war of 1973 showed just how effective an integrated air defense could be). Significantly, it also made this air defense mobile and thus able to advance with any Soviet offensive.

* With the third generation of jets, the West's introduction of new technology slowed down as the Soviet rate sped up.

Suddenly the Warsaw Pact had offensive airpower with counterair, air-to-ground battlefield, and deep-strike capabilities - as well as pilots who were well versed in their new roles. By 1980 the Soviet Union had more third-generation planes on the central front than NATO had total aircraft there.

Today Soviet avionics still lag behind, but in other respects Soviet deployed aircraft technology generally matches all but the West's most advanced F-15 and Tornado.

Overnight the previous NATO complacency about air defense for Western Europe's quite soft and relatively few rear targets became a liability. And ''the prospective locale of a battle for air supremacy,'' in Karber's words, ''moved several hundred kilometers west,'' making it ''NATO's ground units rather than those of the Warsaw Pact that will receive disproportionate losses from air attack.''

(This precise estimate of the impact of the Soviet aerial buildup is not universally shared. US Air Force Lt. Col. Donald J. Alberts' forthcoming Adelphi paper for the International Institute for Strategic Studies is far less concerned about the air balance on the central front than on NATO's flanks. Colonel Alberts sees even the present inferior numbers of NATO fighters as adequate for defense of the central front. This assessment is based on NATO's continuing superior combat radius, ordnance tonnage, and sortie rate. In the event of war, however, NATO air losses would be much heavier than a decade ago, and any surprise Warsaw Pact attack would be much more devastating.)

Since 1965, the Soviets have also made fully mobile all their 26 Category 1 divisions forward-based in East Germany, Poland, and Czechoslovakia (as well as their four additional Category 1 divisions in Hungary). Long gone are the days when the Soviet footslogger envied the few officers who got to ride in lend-lease Studebakers.

Qualitatively, deployed technology in which the Soviets excel, according to Karber, includes: SAMs; aircraft sheltering; armored, vehicle-mounted antitank guided missiles; artillery (with better range, rate of fire, reliability, and barrel life than Western counterparts); the D-30 122-mm howitzer; high-velocity, smooth-bore guns and automatic loaders for antitank weapons; chemical warheads; the 240-mm self-propelled general support rocket system for dispersing fragmenting bomblets and large numbers of mines (with range, accuracy, and ammunition effectiveness comparable to what the US Army will deploy only in the mid-'80s); and multimission Hind-D attack helicopters.

''When our new machines come in, maybe our systems will have 10 percent superior performance over theirs,'' notes Karber in an interview. But ''today they are superior just because we do not have a counterpart'' to various Soviet systems and are slow in procuring them.

In other conventional military fields, the West's deployed technology - and certainly its reliability of hardware because of quality control in manufacture - is superior. In the past decade the gap has narrowed dramatically, however.

In drawing-board and soon-to-be-deployed technology in general the West also retains the lead. Broadly, the area of greatest innovation currently favors firepower (defense) over mobility (offense). Increasingly, if a weapon moves, it can be targeted in real time and hit by ''smart'' precision-guided munitions.

Quite apart from the differential impact of current technology in favoring defense over offense, today's dynamism in the state of the art suggests to the ''technologically exuberant'' Americans (and Japanese) that they can hope to stay five to 10 years ahead of the Soviets. Technological trends are notoriously hard to predict. But so far as anyone dares forecast, computer and other frontier technology is expected to continue its headlong rush at least through the early '90s.

Under these circumstances the ever-new generations of computers, VLSI (very large-scale integration for superfast processing of data), fiber optics, infrared sensing, and even more exotic technologies favor the West.

These technologies have military applications, including miniaturization, fire-and-forget submunitions, air-to-ground and air-to-air weapons, map plotting (for conventional as well as nuclear cruise missiles), pilotless reconnaissance drones, and both performance and redundancy of control, command, and communications systems. Redundancy is duplication in order to ensure that at least some systems survive in battle.

Thus far the Soviets have not developed the information-processing speed needed for real-time surveillance and true fire-and-forget weapons. (Such weapons reroute themselves in flight to seek out moving targets without further guidance from the launcher.)

The West has developed such a capacity, though it is slow in deploying the hardware because of the inefficiency of putting a $400,000 ''brain'' into a $50, 000 missile.

With all these complications, how can the East-West manpower and weapons ratios be put into perspective?

Here the Pentagon offers some assistance - and some comfort to NATO - with its complex, controversial, and classified ''net assessment'' of each side's weapons. This can be displayed statistically in the form of ''armored division equivalents.''

In this evaluation the Pentagon gives Western technology and firepower a clear edge. In fact, the Pentagon reduces the raw numerical 2.2 to 1 Warsaw Pact advantage in major combatant weapons to only a 1.2 to 1 advantage in armored division equivalents.

So is General Rogers's concern about today's conventional balance justified? Or is the military just crying wolf?

Clearly, politics, public image, and interservice rivalry are all involved - and not just sheer military necessity. That is probably inevitable when issues both of survival and of billion-dollar appropriations arise.

But this time around a lot of those who previously were skeptical are convinced there is indeed a genuine wolf - if not growling at the barn door, then hunting in the woods and requiring attention by the prudent shepherd.