REPUBLICAN EXPRESSIONS of gleeful horror at recent public discussion of the Stealth radar-proof airplane may be good partisan politics, but they are bad history and worse national security policy.

Henry Kissinger claims the Ford administration successfully kept the lid on the program. Ronald Reagan claims the Defense Department has given the Soviets a 10-year headstart on countermeasures. And Gerald Ford claims Stealth won't affect the strategic balance for 10 years. All are wrong.

Public discussion of Stealth began on Friday, July 23, 1976, during Ford's administration, in the lead article of Aerospace Daily. Here are some excerpts from that article, titled "Lockheed's Kelly Johnson Building 'Stealth' Aircraft":

"Kelly Johnson is back.

"The nation's premier aircraft designer has returned to the famous "Skunk Works" at Lockheed, where he is building a new 12,000-pound, one-man "stealth" aircraaft. It is due to fly in about two years.

"The program is sponsored by the Defence Advanced Research Projects Agency (DARPA) . . .

"The goal is to reduce aircraft visibility through new technology. Lockheed was chosen from a field that also included McDonnell Douglas and Rockwell International on the strength of Johnson's conviction that he could do the job . . . Lockheed had . . . ambitious ideas in mind. The challenge was sufficient to lure Johnson out of retirement.

"The program is cloaked in tight security. Calls to Johnson's office . . . were not returned. It is known, however, that the Air Force and DARPA have been searching for ways to reduce aircraft signatures through combinations of aerodynamic configurations, absorptive materials, paint schemes and electronic countermeasures."

Whether or not Aerospace Daily's specifics are correct, it is clear that all of the information published and released during 1980 contains not one detail that was not in this 1976 article. In 1980 the Soviets and the world know only one thing they didn't know under Ford: They know the program has been a success.

Does this place the Soviets any nearer to countering Stealth? Certainly not; they know no more specifics than they knew in 1976.

Are they now motivated to work the problem harder? Most unlikely. As they read Aerospace Daily, the Soviets knew of Kelly Johnson's phenomenal 100 percent success record: at least seven successful all-new designs running from the World War Ii P38 fighter to the Mach 3 -- plus SR71 reconnaissance plane, each a major step forward in its time. Unless they were fools, the Soviets must have assumed a high probability that Johnson would succeed on this one and their $100-billion investment in anti-aircraft defense would become even less effective than it is today. They must have begun a serious effort to develop countermeasures.

Nothing in this year's public discussion has given the Soviets any reason to increase this effort. Fortunately, there has been no disclosure of specific Stealth technology details, for which the public has no need or use. While it may be that there is no counter to Stealth, there is no point in tempting fate.

While much has been said about the dangers of disclosure, the far more significant advantages of disclosure have been neglected.

Suppose Stealth were kept completely secret until the outbreak of a nuclear war, when Stealth-hidden cruise missiles or bombers would blow the Soviet Union to smithereens. If this happens, Stealth would have failed, since Soviet missiles would at the same time be blowing the United States to smithereens.

The primary target of any strategic weapons is not the adversary's assets. It is the adversary's mind. Stealth will be successful if it convinces Soviet leaders that aggression will cost them more than they will gain from it. This is deterrence. If Stealth were kept secret, it would have no effect on Soviet decision-making and would fail.

The question is of the balance between the need for secrecy to inhibit countermeasures versus the need for disclosure to intimidate. While the ideal course may be to hold a major new weapon secret until it is actually in the field, there are often good reasons to disclose the existence of such a program much sooner.

Unfortunately, much of the world is becoming increasingly convinced that the United States has lost military primacy to the Soviet Union. This conviction is growing not because of anything our allies or neutrals see for themselves, nor because of anything they hear from the Soviets. It is growing because of an unceasing campaign, principally by members of past and potential Republican administrations, to bad-mouth the military capability of the United States.

That this bad-mouthing is factually wrong, that it is based on specious selection and dishonest distortion of military measures, is beside the point. If we tell the world we are weak, why should it not believe us, since what rational reason can there be for a superpower to portray itself as weak when it is not?

So we now have our allies for the first time beginning to question our capability. Such questioning may encourage them to do more for their own defense. But its primary thrust is to loosen the alliance network which supports us all, and there is no way that can be beneficial.

We have not yet succeeded in convincing the Soviets of our inferiority. Their analysts are as good as ours, and there is no evidence that they have projected the outcome of military confrontation as anything other than dismal for the Soviet side. Probably we have not yet persuaded the Soviets of our own self-intimidation, although that is less clear. But if we continue the way we are going, we will do it. At that point they will be on the edge of major aggression, and we will all be on the edge of the next and last World War.

The leadership of the present Defense Department is well aware of this problem. It was not partisan politics for Defense Secretary Harold Brown to invite the press to watch demonstrations of the cruise missile or the Copperhead tank destroyer -- major breakthroughs the Soviets are many years away from countering or duplicating. It was understanding that it is not enough to have the right stuff; we must also show the world we have it and we have confidence in it.

Stealth is a fundamental military breakthrough, comparable to the invention of radar. The world doesn't need to know how it works, but the world does need to know we have it. It began to have a major beneficial effect on the psychological strategic balance the moment Brown put it into the headlines. The cause of peace and security is most probably served by shouting the existence of this development from the housetops. The question is not why we are doing this; the question is why we didn't do it sooner.