Europe's arms imbalance not apt to change soon. Money and politics restrain West from boosting its forces

There are two ways to redress the conventional military imbalance in Europe - up or down. Both look impossible. Going up would mean for NATO to add 20 percent in manpower, to double or triple tanks, and to quintuple antitank guns. This is utterly unrealistic. The United States is not going to reinstate the draft; West Germany is not going to compensate for a declining birthrate by recruiting women; and NATO members are more likely to curtail than to expand their defense budgets.

Moreover, sophisticated modern weapons are increasingly costly, so even the same amount of dollars buys fewer and fewer planes or artillery pieces. Yet the mood of publics that are breathing a sigh of relief at the prospect of finally reducing nuclear weapons is hardly one to tolerate increased taxes for more conventional weapons.

So could savings from nuclear weapons scrapped under any arms-control agreement be diverted to pay for conventional arms? At least one American study has begun to look into this question - but analysts at NATO's political headquarters in Brussels very much doubt that electorates will funnel surpluses into armored personnel carriers rather than into, say, public schools.

Moreover, even if all nuclear savings could somehow be devoted to conventional weapons, this would hardly be enough to jack nonnuclear forces up to East-West parity, since nuclear weapons are so much cheaper in bang for the buck. NATO's original embrace of nuclear deterrence came, after all, when the Western alliance realized that it was never going to fund the conventional-force goals it planned in Lisbon in 1952 to match the huge Soviet land army, and that NATO could achieve the intended deterrence of war much more cheaply with what was then the West's nuclear superiority.

Theoretically, one could argue that Western Europe, with a combined economy equal to America's and almost double the Soviet Union's, and with a population greater than the Soviet Union's, could afford to match Soviet armies. But political reality decrees otherwise. Democratic societies simply will not militarize themselves to the degree the Soviet Union does.

The alternative route to equalization - getting the Soviets to build down their conventional forces - seems equally implausible. This is the panacea that West German leaders are seeking. And politically the West is endorsing the idea, partly out of an unexamined belief that if a little disarmament is good, a lot of disarmament is better - or at least out of a conviction that that's the way voters reason.

Yet so far, the West has no concrete idea of what it wants out of any reductions, beyond the vague hope of thinning out Soviet forces forward deployed near the West German border. And it is hard to discern what incentive the Soviets might have to forfeit their advantage - or what inducement the West might offer that would not lose more than it would gain. The West's professional military in particular is dubious about the whole idea.

Nor are there any signs that thorough military studies of options will be carried out before NATO is due to formulate a unified position on conventional arms reductions in December. ``No NATO nations, no NATO structure, has ever calculated if it's right'' to aim for reductions, comments one European general involved in meshing military strategy and civilian policy. ``We lack the long and [quiet] and solid work of what we called the general staff in former times.... I doubt very much that a reduction in conventional arms can be to the advantage of the weaker [side].''

Indeed, what is striking about the surge of alliance interest in conventional arms reductions in the wake of the Iceland superpower summit is that the intra-alliance debate has thus far neglected military substance so totally in its exclusive focus on the forum of arms reduction talks.

France and West Germany want an Atlantic-to-the-Urals format, without strict alliance discipline (since Paris wants to avoid any appearance that it is rejoining the NATO military command, and Bonn very much wants to include the French). The US wants coordinated negotiating by the alliance above all else. Substantively, the various candidates for shrinkage in the conventional field - military manpower, weapons, and mobilization - are all problematic for the West.

Negotiations about manpower cuts have already been going on for 13 desultory years in the Mutual and Balanced Force Reduction (MBFR) talks in Vienna covering the two Germanies, Czechoslovakia, Poland, and the Low Countries. The Western interest there - asymmetrical cuts in the Soviet-bloc ``overhang'' of some 230,000 troops - has been considered self-evident.

Yet it is hard to see what payable Western concessions might bring the Soviets to agree to disproportionately greater Soviet reductions - especially since even without negotiations the population curve in West Germany will probably lead to a significant unilateral drop of perhaps 45,000 NATO troops on the central front.

More fundamentally, a number of Western analysts are leery about what might result even from asymmetrical troop cuts. An American diplomat warns against pursuing cuts just because it is thought necessary politically.

``Are we really interested in conventional reductions? Is that the way to hit the conventional force overhang?'' he asks. He and some others wonder if NATO's own front line would still be able to hold off an all-out assault for as long as a week or two, as it presently can, if this already brittle line were to be thinned out even more.

The doubters - and they include not only hard-liners, but also those on the center-left of the political spectrum - go further to ask what would be accomplished even by more substantial withdrawal, say, of units of the 60 divisions in the western Soviet Union behind the Urals. They question the assumption that the longer advance warning of Soviet mobilization from such deployment would in fact give the West a longer period in which to mobilize before the first shot, given increased political resistance to mobilization in the West under such conditions.

``In a time when you can shift 80,000 men overnight by aircraft, I have some doubts,'' the European general observes. ``If you look at the map, the Urals are more or less at the western part of the Soviet Union, so I would still feel Soviet superiority even [if excess Soviet troops were] east of the Urals. And we would never be able to reverse that.''

The second possible object of negotiated reductions - armaments - is also unattractive from the West's point of view, since even asymmetrical reductions could hamper NATO's prepositioning of equipment for crucial American reinforcements.

The third possibility - inhibiting the Soviet ability to mobilize reserves - could also be problematic in limiting as well the critical West German capacity to mobilize reserves. (If such restrictions are introduced in any broad Atlantic-to-Urals context, the Swiss and other neutrals have already given notice that they would not join in.)

The remaining alternative - and NATO's most probable course, in the view of most sources interviewed for this series - is muddling through with the present conventional inferiority in the hope that the new Soviet turning inward - and the horror of today's high-tech conventional as well as nuclear weapons - will continue to deter war in Europe for the next 40 years as the nuclear balance of terror has for the last 40.

Last in a series. Previous articles appeared Nov. 4 and 5.