Can NATO lessen its nuclear tilt?

Making nuclear war in -Europe more unthinkable is the aim. Nonnuclear readiness and ''smart'' technology are the means. Money is the stumbling block. This is the consensus that is finally shaping up between NATO military and civilian planners. Both sides are seeing the need to become more realistic, says Anthony H. Cordesman, an editor of Armed Forces Journal International.

For more than a decade, the generals (in the eyes of civilians) had cried wolf about Western weakness and demoralized citizens rather than galvanizing them to action - while civilian planners (in the eyes of the military) ignored the Soviet buildup of tanks and multiple rocket launchers.

Today, the generals are finally pulling back from asking for surrealistic force levels that could win and not just deter a European war. And civilians who have tended to extrapolate from superpower strategic parity - and just assume the European balance must be equally healthy - have finally begun to check the sobering bean count.

Such convergence is all well and good. But then comes the hard task of defining the convergence more concretely - and translating it into tough policy decisions about priorities, trade-offs, and budgets.

The goal is by no means as simple as rendering nuclear war in Europe totally unthinkable. That might, perversely, make conventional war all too thinkable for an aggressor - by letting him form armored breakthrough concentrations with impunity, in the assurance they would never be thwarted by a nuclear strike.

''This is something people have to keep in mind,'' an officer of West Germany's Bundeswehr warns. ''Nuclear war is not more frightful than conventional war. The problem is not to avoid nuclear war - but to avoid war,'' by keeping the entire deterrent credible.

(Ex-Defense Secretary Robert McNamara and a few other prominent Americans who don't fully agree with this reasoning are calling for a NATO renunciation of the first use of nuclear weapons under any circumstances. But mainstream NATO thinking holds that a threat of nuclear retaliation is necessary both to keep the Soviets from massing forces that could punch through NATO defense, and to deter war of any kind, conventional or nuclear.)

In any case, both those who would renounce the use of nuclear weapons and those who would reduce the numbers of such weapons hope to avoid that stark NATO choice between surrender and nuclear war-fighting. And they hope to do so by making the many uncertainties of the European balance work for NATO rather than against it - through readiness and technology.

Readiness includes everything ranging from ammunition stocks to reserve troops. It is unglamorous and relatively inexpensive but could bolster NATO defense enormously.

Technology entails harnessing ''smart'' weapons to interdict those crucial Soviet second-echelon shock troops well behind the Soviet front line. It is glamorous (but maybe not glamorous enough), wildly expensive - and could bolster NATO defense more than readiness.

Readiness was the main objective of the Long-Term Defense Plan NATO adopted in the late 1970s. The plan involved stocking equipment to enable six US reinforcement divisions - so far 42/3 of them are in place - to fly to Europe immediately in an emergency. It rebuilt US stores of ammunition to 60 to 90 days.

The plan included a major sheltering program to protect NATO planes on the ground - and initiated a comprehensive NATO air defense system. It also outlined potential appropriation of civilian planes and other assets in wartime (on the successful British pattern in the Falklands war).

But it didn't do a number of things its main instigator, then-Undersecretary of Defense Robert (''Blowtorch'') Komer considered essential. It did not construct passive defenses - not even hedgerows - on the North German Plain. It did not get far on ''standardization'' and ''inter-operability'' of the various allies' national equipment. It did not develop a capability for rapid repair of runways.

Nor did the long-term plan reorganize existing European reserves or generate new ones to provide instant territorial forces in wartime. And it did nothing about putting light mountain troops in the hilly central sector to relieve the heavily mechanized NATO brigades there for mobile reinforcement of the very thin NATO line on the North German Plain.

All these things are still critical, Mr. Komer says in an interview, if NATO is to withstand an attack for more than a week or two.

The new technology is much more futuristic. It would use pilotless reconnaissance drones and probably conventional cruise missiles to spoil second-echelon concentrations of Soviet forces. (Such interdiction capability could prove far more ''credible'' than the threat of a nuclear strike, since there would be fewer inhibitions against its use, and presumably no requirement of a presidential release.)

The new technology would imitate the Warsaw Pact in moving toward area (as distinct from individual target) weapons like multiple rocket launchers - and would move toward area ''smart'' weapons. It would allow aircraft at some distance from targets to fire sophisticated submunitions for ground-attack support as well as deep interdiction. It would go in for Buck Rogers-type innovations like aircraft vectoring in flight, accelerating along an axis a computer cannot follow.

In utilizing the new technology in the seesawing balance between superhard ''special armor'' and armor-piercing projectiles, NATO would also try to improve its antitank guided missiles and to deploy enough of them to offset the Warsaw Pact superiority in tanks.

But is all this feasible, politically and financially?

Politically, it is getting more feasible. The West Germans - who back in the '60s thought that deemphasiz-ing nuclear weapons meant they would be left naked - have become converts to the wonders of conventional technology. Even the US Army - which often is suspicious that new technology will reduce the Army's role - is getting excited about the prospects.

According to a British civil servant, NATO circles are coming close to bestowing on new technology the sanctity of motherhood.

Practically, however, no NATO member country has yet put its money where its mouth is.

The reluctance is understandable. Bang for buck, nuclear weapons are far cheaper than conventional weapons. And in a world that has seen the end of its exuberant two-decade-long postwar economic expansion and is struggling to get out of oil-crisis recession, any increase in military budgets looks highly problematical.

It is hard enough for NATO members to live up to their current pledge of 3 percent yearly real increase in defense budgets - and this 3 percent is widely viewed as the minimum needed just to sustain present levels of forces and equipment.

It is also highly unlikely the US would sacrifice, say, its glamorous B-1 program in order to fund a much less jazzy conventional interdiction program - or that France would sacrifice its new missile submarines or Britain its expensive Falklands badge of honor to the cause of conventional defense in Europe.

Nor have various cost projections for a high-confidence conventional defense impressed observers with their verisimilitude. Virtually no specialist interviewed thought the 4 percent yearly increase recommended by NATO commander Gen. Bernard W. Rogers - or even the $20 billion program recommended by the American Academy - would go far enough beyond readiness to pay for the new gadgets envisaged for the 1990s.

Yet there is an urgent need to reassure the public - as the peace protests show - that nuclear war is not just around the corner. One of the most persuasive ways to do this, NATO officials contend, might be to build a believable conventional defense: not one that comes anywhere near matching the Soviet-bloc numbers of weapons, but one that could be expected to blunt any sudden Soviet thrust - and thus deter any attack in the first place.

So what is the bottom line?

Prudence calls for reducing our dependence on nuclear weapons in the most heavily armed spot on earth, the East-West military fault line in Central Europe. Rational analysis suggests this is a reachable goal technically. Economic and social considerations, however, suggest that it is an impossible goal financially.

The rest is up to politics.