The Soviet leader made his case in a persuasive fashion, according to an official who was present, explaining his concept of force reductions to a level of "reasonable sufficiency."

LEAD: How sincere is the Soviet Union about devising a new military doctrine that emphasizes defense and what its officials call a "reasonable sufficiency" of forces?

Yes, but at too great a price for our economy and far beyond the limits of reasonable sufficiency.

Thus far, his new ideas of an interdependent world replacing one of global class struggle, and of "reasonable sufficiency" in national defense, have not produced markedly different Soviet behavior.

The agreeing sides will make efforts to provide for their own security based on the principle of reasonable sufficiency of armaments and armed forces.

Instead, Gorbachev emphasized civilian economic priorities and reasonable sufficiency in defense over the professional military's perceived requirements.

The Soviet Union abides by the principle of reasonable sufficiency of armed forces and armaments.

Soviet theoreticians use the phrase "reasonable sufficiency," while the military favors the term "defense sufficiency," which allows them more flexibility in determining force levels.

More significantly, he supported proposals to establish a Pacific nuclear-free zone and to lower levels of troops and armaments to that of 'reasonable sufficiency'.

He claims they now agree on the "absurdity" of stockpiling vast quantities of weapons and on the doctrine of a "reasonable sufficiency" for defense.