EXPECTED ratification of the superpower treaty eliminating intermediate-range nuclear force (INF) missiles is focusing attention once more on the conventional imbalance in Europe. For two decades the West counted on nuclear weapons to offset Soviet conventional superiority in numbers of weapons and troops on the central front. Even in the 1980s after the West lost European regional nuclear superiority and therefore (presumably) the ability to control escalation, nuclear ``deterrence'' - prevention - of any kind of war still seemed robust. Even if NATO could no longer rationally threaten to resort to nuclear weapons to avert defeat in a conventional war, it still could and did threaten an irrational escalation to a nuclear war that neither side could control. This has been a powerful disincentive, NATO allies contend, to any possible Soviet thoughts of launching an attack on Western Europe. In this context the conventional imbalance didn't matter so much.
Now, however, with the West's most effective nuclear weapons being removed (along, to be sure, with four times as many Soviet warheads), the conventional imbalance again looks more important and less amenable to being offset by nuclear force.
Two basic issues therefore loom large as East and West prepare to open new conventional arms control talks later this year:
-Just how bad is the conventional imbalance?
-Can it be rectified through negotiated arms reductions?
The Monitor, after interviewing NATO and government officials and military officers in Bonn, Brussels, and elsewhere in Europe, explores some of the answers today and tomorrow on these pages.
ON May 10, 1940, Hitler's Wehrmacht mounted a surprise attack on Belgium and France in the Ardennes Forest. On the face of it, it was a foolhardy offensive. The hilly spruce and oak woods here are inhospitable to tank advances. The superb French Army, with its British, Belgian, and Dutch allies, had just as many divisions and tanks as the Germans. And the allies also enjoyed the traditional advantages of the defense, enhanced by the Maginot Line and Belgian forts.
Yet the German blitzkrieg (``lighting war'') machine suddenly massed seven tank divisions for a local superiority in armor and sliced through the allied lines. Within days the Germans were at the English Channel. Within a week they destroyed the French Army. Within six weeks France capitulated.
Today Soviet forces practice the same blitzkrieg tactics that Hitler's Army pioneered. They have an overall tank superiority of 2.3-to-1 on the central front. West Germany - only 150 miles wide and with much of its population and industry close to the East-West German border - has less depth for maneuver than did France in 1940, and cannot make the classic trade of space for time. In any war NATO would therefore have to protect front-line West Germany with unyielding forward defense - the hardest kind.
Then how risky is today's conventional imbalance between the Warsaw Pact and NATO? Could the existing Soviet superiority in heavy weapons on the ground ram a spearhead through NATO defenses that would repeat the Battle of the Ardennes?
The honest answer must be: Nobody knows, either in the West or the East.
The reasons for confusion are myriad. They include the old apples-and-oranges problem; the varying projections of possible war scenarios; uncertainty about political decisions to mobilize; the historical unreliability even of full conventional equality to deter war; Soviet reluctance to take risks; and, most recently, the raging controversy among Western strategists about the mathematical ``Lanchester model'' that is routinely used in computer projections of war games.
Surprisingly, given the heated arguments about the imbalance, the basic ``bean count'' is not really in dispute. What the raw numbers mean, however, is very much in dispute.
Numbers and apples
The numbers show an approximate equality in NATO and Warsaw Pact troops in the broad Atlantic-to-the-Urals area of the new conventional arms talks due to open this fall: 2.3 million for the Warsaw Pact to 2.4 million for NATO, according to the International Institute for Strategic Studies (IISS) in London. In the smaller but more crucial ``central front'' of West and East Germany, the Benelux countries, Czechoslovakia, and Poland, however, the institute shows a 1.2-to-1 advantage in manpower for the Warsaw Pact. On the central front these 800,000 NATO troops are organized into 32 large divisions, the 1 million pact troops into 48 smaller divisions.
In heavy weapons on the central front - the artillery, tanks, and other armor that could be used to seize and hold ground in an offensive - the numbers get even more unequal, for a 2.6-to-1 Eastern advantage in artillery, 1.4to1 in tanks, and 2.4to1 in armored personnel carriers, the IISS reports. Statistics from NATO and various Western defense ministries roughly agree on these points, and even peace-movement critics who worry more about Western high-tech offensives into Eastern Europe than Soviet tank offensives to the West don't challenge these ratios as such.
The various military studies also agree that the quantitative imbalance in favor of the Soviet bloc increased over the past generation. According to Phillip A. Karber, vice-president of defense consultants at the BDM Corporation, Soviet leader Leonid Brezhnev carried out a major buildup in conventional weapons in Europe between 1965 and 1980 that widened the Soviet-bloc lead in tanks from 2.3to1 to 2.7to1 (though the IISS gives today's ratio in the broad alliance area as 2.4to1); in armored personnel carriers from 1.1to1 to 2.6to1 (the IISS says today's ratio is 2.4to1); and artillery from 1.2to1 to 2.6to1 (here the IISS concurs).
That makes for an aggregate Soviet-bloc advantage in ``armored division equivalents'' of 1.2to1, according to Prof. John Mearsheimer, citing US Defense Department calculations.
Where the mushrooming studies of the European conventional balance do not agree is in their interpretation of these raw data.
The main problem arises in trying to compare apples and oranges, since NATO invests its defense money quite differently from the Warsaw Pact. NATO's proportion of logistics to fighting men is much higher than in the lean Soviet-bloc divisions, for example. And the Warsaw Pact puts much more of its firepower on tanks and other armor on the ground, while NATO has put half of its firepower, the Soviets say, onto aircraft. Yet the Soviets have many more airplanes - though less well armed - in Europe.
Besides, quantity says nothing about quality. Ever since World War II, the West has held a technological lead over the East. Yet that lead, at least in weapons systems themselves (tanks, guns, planes, and the like, as distinct from such things as miniaturized computers, sensors for target acquisition, and avionics), has been greatly eroded in the past two decades, and the Soviet Union has even fielded some entire new systems in advance of the West.
Moreover, quantity and quality play out differently, depending on whether they apply to offense or defense. NATO is strictly defensive, and strategists still accord the advantage to a defense that is dug in, exploits natural barriers, and knows the terrain it is fighting on. In the old lower-tech days, the rule of thumb used to be (despite the Battle of the Ardennes) that an attacker needed a 3-to-1 local advantage to be confident of victory against a prepared opponent.
Today nobody is sure whether higher-tech conventional weapons follow the same rules. Fortunately, they have never been sufficiently tested in battle to prove whether today's warfare is really defense-dominant (as in the World War I trench stalemate) or offense-dominant (as in a successful blitzkrieg). The standard Lanchester model used for war gaming sets a lower ratio of equivalence than the old 3to1, but still assumes the defense will hold if the attacker has a local superiority of only 1.4to1.