As the Congressional Dollar Hunt gets under way each spring, the contending traditional halloos of "Guns!" and "Butter!" come wafting down the Mall. Those who have seen the spectacle before -- the dozens of subcommittees galloping across one another's paths, the spills into damp confusion, the staff hounds losing the scent, the thin, bedraggled quarry -- may be forgiven if they wince and turn away to contemplate instead the cherry blossoms or the pick-up softball games. If they must try to catch the poor trembling little thing, isn't there a simpler way?

Probably not. But one problem contributing to the incoherence of the whole effort is that, regarding defense, almost the whole public budget debate is couched in terms of guns versus butter. The question of what the guns are for is relegated to a relatively minor role.

The guns and the people who carry them are, after all, for deterring the Soviets and their clients from war, or defeating them if it comes to that. Assessing what you need for defense is thus a fundamentally different kind of problem from that of financing NASA's trips to the moon or distributing food stamps. There is a rational player on the other side trying to make the job harder -- trying to be absolutely sure that, if he feels he needs to, he can kill you.

Thus what the Soviets are doing about buying guns should at least be an item of more than secondary interest. The lack of attention to this is budget time in the press and in much of Congress is a habit of some years' duration, due in part to the Pentagon's having lost so much credibility in the Vietnam era that many people shy away from discussing "The Threat." It has connotations of scare tactics, beribboned briefers claiming superior knowledge and infallibility -- all that. The revulsion against that era's excesses has carried over, for many, into years of reluctance to invest in and maintain our armed forces, a reluctance rationalized in various ways. As a result, our margin for error is gone.

From the mid-'60s to the early '70s, we poured about a quarter of a trillion dollars in military resources into the Vietnam War. Most of what it bought is still there in the jungle, either rotting or being used gleefully by the Vietnamese in their gambols around Cambodia and elsewhere. But the Soviets, in the decade of the '70s, spent on their military nearly a third of a trillion dollars over and above what we did. And they still have a great deal of what they bought with it.

Today the Soviets annually spend nearly $80 billion more on the military than we do -- well more than double the percentage of GNP we spend -- and their budget continues to grow at least 3 percent in real terms. (Those are the CIA's figures; academic critics and the Chinese government say Soviet military growth is double the CIA estimate." Our growth would keep pace with Soviet growth -- albeit from a position a ong way in the rear -- if it weren't for inflation. But the Soviet real growth in the military is real real growth. Ours isn't. Ours is calculated on the assumption that there will be an average of around 9 percent inflation for all of Defense next year.

Read the double-digit headlines, then pretend you are a Soviet military leader and try to repeat that 9 percent figure to yourself without chuckling merrily. When the Consumer Price Index goes up by 18 percent, the law requires that Social Security payments keep close pace. That's called zero real growth. When inflation is well up in the double digits but defense goes up 3 to 5 percent above the hokey 9 percent assumed inflation rate, that's called 3 to 5 percent real growth.

Assuming that inflation rate for defense, the United States will have "real" growth in defense at about the same rate as the Soviets next year -- but only as long as you are willing to forget about all the weapons programs that are so under-costed that they have built-in cost-overruns waiting to be discovered; forget about fuel that is priced to assume no increases above today; and forget about sergeants whose pay raise is -- yet again -- half or less of the increase in prices for what their families have to buy.

Particularly because of this latter point, a U.S. defense budget at the currently proposed level, if inflation were accurately reflected, would show real decline, not real growth. The administration says military programs will not suffer because of inflation; but until the corrections are proposed, the real real question in the current debate is how well can we handle the Soviets militarily if we march backward while they're double-timing forward?

No, we shouldn't be trying to race the Soviets to the bankruptcy court. Yes, our allies make some contribution to the common cause -- large in the aggregate, but not well coordinated -- and they should make more. Yes, economists can differ about the exact amounts, in rubles or dollars; in rubles the Soviet lead is somewhat less (but its growth rate is higher). And, yes, it is outputs (real military capability) not inputs (dollars and rubles) that ultimately make the difference.

But different levels of military spending on the order of a third of a trillion dollars within a decade, together with diverging growth trends, produce widening gaps in capability that begin to affect our ability -- and our will -- to prevent the Soviets or their clients from doing things like dominating the Persian Gulf and Finlandizing Europe and Japan. That third of a trillion dollars' difference is one big reason why the Soviets have four times the tanks we have and are producing tanks, guns and aircraft at two to three times the rate we are; why they begin construction of a new general-purpose submarine about once every five weeks while we start one a year; and why they have 25 new divisions equipped for chemical warfare, some of which are playing an exhibition season against Afghan tribesmen. To expand the numbers slightly in an expression made famous by the late senator Everett Dirksen: a third of a trillion here, a third of a trillion there -- before you know it, it adds up to real money.

In other words, at some point the standard debating points become merely interesting wavelets on the surface of the Soviet military flood tide. The Soviet military budget exceeds ours today by about the same percentage by which Germany's exceeded Britain's in 1935. It is not profitable to let the annual dollar hunt become a ritualized happening like the favorite well-worn argument an old married couple has at regular intervals. New facts -- such as the Soviet buildup -- ought to change the nature of the debate. As a fine young author put it 40 years ago, in his dissection of the hauntingly similar British defense budget debate in the 1930s. "Why England Slept?": "We should profit by the lesson of England and make our democracy work. We must make it work," John F. Kennedy wrote, "Right now."