In the lecture hall we had been served up a rich plate of Soviet threat and now, in one of the seminars that the Naval War College's annual strategy forum breaks down into, we were discussing "national will." Heads were being shaken over whether the United States has the stuff to handle some of the heavier military scenarios that might come to pass.

Well? Would the country put itself in harm's way in the Persian Gulf 1) when we could not expect to apply anything like the conventional power ashore available to the Soviet Union; 2) when we might not enjoy all that much support from our European allies, even though it would be for their oil needs, far more than for our own, that we would be fighting in the first place; and 3) when we might not get that full a degree of support either from the Persian Gulf friends we would be there ostensibly to defend?

We sent a certain message of resoluteness, to ourselves as to others, when we elected Ronald Reagan. But that eases a much smaller portion of our strategic cares than many of his more ardent supporters concede. It will be a long time before the country will have the military power to do what the administration says must be done, by military power, to protect our interests in the Gulf.

Suppose, for instance -- to cite one contingency suggested by Assistant Secretary of Defense Bing West -- that Moscow "seizes the Gulf" by a "blitzkrieg" and, hand on Europe's oil tap, demands that Europe disband NATO and send American troops packing.

It was obviously with something of this sense of vulnerability in mind that former defense and energy secretary James Schlesinger suggested, in an ominous tone, that the West is now in the fix of having to depend on "Soviet forbearance" in the Gulf.

Navy Secretary John Lehman asserted that in that region the United States has to be prepared to go into "the highest-threat areas of Soviet capability." He indicated that the United States would not be so prepared until it has the 600-ship, 15-battle group Navy that the Reagan administration intends to build by 1990.

Meanwhile, until military power on those dimensions is built, much depends in the military view now current on "national will." It is a flexible concept. In our seminar, as from the lecture podium, it was being used not so much as an expression of informed national consensus by as a euphemism for support of a policy of intensive rearming and standing up tough to the Soviets.

But there were other echoes. "National will" was being evoked in kind of a mythical way going beyond the determination to use power already in hand. It was being wielded almost as though it were a real substitute for power not yet in hand. If we had adequate power, the current ran, we could apply it. Not having such power, we must project "national will," as though to psych ourselves as well as our foes. Something like that was in the Newport air.

Our seminar conducted a revealing discussion of the "rapid deployment force," which to most Navy people, by the way, seems not a force but a faint plan or a distant hope, if not a joke. The consensus was that you might get more deterrence value from a military tripwire presence on the ground than from a "force" that the politicians might or might not decide to order up once a crisis flared. Next question: Would not the military prefer to have the political debate take place before rather than after American forces came under fire? Yes, but. . .

When military people say that the strengthening of forces and taking of firm positions can diminish the prospect of war, they deserve a careful hearing. They may be right. They will bear the brunt of civilian miscalculation. At Newport, I met a number of former Vietnam POWs, impressive men with, I thought, a special inner gravity, and I left them feeling reinforced in the view that we must be very careful about what missions we ask the military to perform.

At the same time, I got the feeling that in the Navy (and presumably the other services) and in the civilian leadership, a certain measure of confusion and illusion is evident. Reagan's victory and the general atmosphere of military alarm have cheered and even dazzled Navy types who see the first big part of the answer in budgets and hardware and the second in assertiveness. They have the wind, but some part of it could be squandered if the definition of the military threat is not trimmed back to what ordinary people can credit, look at without blinking, and accept paying for over the long haul.

One defense debate may have ended in 1980. The next one hasn't really begun yet, but it should, and it will