In time of war, could Soviets rely on their Eastern allies?

If ever Europe erupted into war, Moscow's allies in Eastern Europe would enhance the Soviet military machine in the initial stages, but they would weaken it - and might even sabotage it - in a prolonged stalemate.

This seems to be the consensus in the Western evaluation of the Warsaw Pact, the Soviet-bloc military alliance that wound up its 18th summit in Prague Wednesday.

It appears to be the thinking in Moscow as well.

This conclusion follows from background interviews with both American and Western European military analysts.

The whole question remains abstract, in that almost 38 years of quite remarkable peace in Europe despite world turbulence has persuaded most observers that a general war is highly unlikely here. Europe ranks far too high among the vital interests of the two superpowers for either one to try to change European allegiances by force. Nonetheless, this conspicuous caution could be weakened if the East-West balance were lost, the same observers believe. Hence the sensitivity of the question of Eastern European loyalties.

Soviet military writers do not, of course, speculate about the prospect of Eastern Europe's wavering in wartime. But the analysis of World War II and the Polish crisis of the past 2 1/2 years suggests that Moscow is paying considerable attention to the possibility.

Thus, in the Soviet assessment of World War II there is a clear recognition that once the tide turned at Stalingrad and Soviet forces began pushing back Hitler's legions, the easiest victories always came not against the Third Reich itself but against troops from Germany's client allies. Some Soviet discussion of this phenomenon suggests a present-day extrapolation to Soviet client-allies.

In addition, the rise of a working-class movement in Poland with anti-Soviet overtones aroused alarm in Moscow about a systemic crisis in the Soviet bloc, a number of senior Western scholars reported after trips to Moscow. Even though Polish leader Wojciech Jaruzelski was able to convince most Solidarity members of the hopelessness of underground resistance inpeacetime 1982, the memory of the Polish partisan network against Hitler Germany in wartime has not been erased. A possible future replay of this also cannot be dismissed.

In any present-day war the greatest Soviet vulnerability in its crucial supply lines to East Germany would be the railroad link across a Poland that has an anti-Russian tradition. Poland, with 36 million people and 15 divisions, has the largest population and army in Eastern Europe. There are only two Soviet divisions in Poland to guard the lines of communication.

The pre-1980 Soviet assignment of an offensive role to the Polish Army in any European war suggests that Moscow thought it could rely on the loyalty of the Polish armed forces so long as Soviet forces were advancing. This would be ensured not only by the Soviet-trained Polish general officer corps and ruthless discipline, but also by the direct Soviet command of all Warsaw Pact air space and Soviet liaison officers distributed throughout the Polish Army.

In line with these considerations, Soviet military doctrine of a blitzkrieg offensive in the European theater would seem to reflect political as well as military requirements of sustained victories.

For the West, the Soviet caution induced by the need for assured victory is a plus. However, it provides only limited comfort for the most critical period for NATO countries: theinitial attack by the Warsaw Pact.

In this period the Soviet Union would haveadvantages not only in its blitzkrieg organization of a much higher proportion of combat to logistics troops (relative to NATO's ratio), but also the undisputed Soviet command within the Warsaw Pact.

To be sure, the NATO-type alliance of fully independent partners who must voluntarily agree on joint reactions confers a long-term strength; there is no risk that a West German captain might turn his artillery battery against his American allies, while there is a real question under certain conditions whether a Polish captain might turn his artillery around.

At the same time, however, the sometimes acrimonious nature of consultations among partners can delay decisions in time of crisis. In particular, in a period of ambiguous mobilization by the Warsaw Pact - as any warning period would be sure to be - Western European nations would probably want to postpone countermobilization longer than the US, in an effort not to seem provocative. Yet this would be precisely the period of greatest danger of a Warsaw Pact breakthrough against inferior numbers of NATO tanks, artillery, planes, and combat troops. And this period would be too early for any Eastern European foot-dragging to Soviet military plans to have developed.