SINCE HE QUIT the U.S. SALT delegation in 1974, Paul H. Nitze has held no formal position with the government. At 72, he is at an age where many contemporaries seek no task more arduous than the compilation of memoirs and no challenge more formidable than reducing a golf handicap.

Nitze, however, has become an administration nemesis in the skirmishing over the SALT II agreement. By the time the treaty signed in Vienna last week is ratified, defeated or withdrawn, Nitze is certain to have exerted more influence on the outcome of the struggle than any other private citizen with the possible exception of Henry Kissinger.

Looking glumly at the fight ahead, one top administration strategist concludes, "Paul Nitze is worth a hundred bureaucrats."

"Henry Kissinger we will have to stroke," says another. "Paul Nitze we will have to beat."

Beating Nitze on a strategic issues is beating the grand master of he game. He was present at the very dawn of the atomic age, and over the past 33 years has helped define its terms, develop its concepts, fashion its strategies and negotiate its guidelines.

His colleagues have included the great names of the postwar policy-making generations: Forrestal, Marshall, Acheson, Dulles, Rusk, McNamara, Kissinger. Dean Acheson described him as "a joy to work with because of his clear, incisive mind."

Others, in assessing Nitze, speak of a deep and dogged intellect, a clarity of thought, a precision of expression, an ability to master complex technical questions and a ruthless and unbending logic.

White-maned, aristocratic in bearing, elegant in dress, Paul Nitze looks every inch the quail-shooting, horseback-riding gentleman farmer he is. He is also an accomplished pianist, has studied archeology and written theological essays.

He was born rich and married richer. With his family he bought, built and developed the Aspen ski resort.

But it is in the area of strategic debate that Nitze's voice rings loudest. He is chairman of policy studies for the Committee on the Present Danger, among the most influential groups of hard-liners.

He is a one-man think tank for Capitol Hill hawks and a source of strategic wisdom for conservative columnists. Although for tactical reasons he has refrained from committing himself to defeat of the SALT II treaty, its foes compare his role to that of Winston Churchill alerting Europe to "the gathering storm" on the eve of World War II.

Friends share Nitze's view that the strategic position of the United States is threatened by an aggressive Soviet strategy plus an increasing Russian ability to knock out all or most of our land-based missiles in a massive attack.

Critics, on the other hand, say that even Churchill's credibility would have suffered had he seen as many "gathering storms" on the horizon as Nitze has detected over the years.

The lessons of Hiroshima

Nitze's views are rooted in more than a generation of debate over the role of nuclear weapons, a debate that began in 1945 amid the rubble of Hiroshima and Nagasaki.

Nitze then was assistant director of the Strategic Bombing Survey, a team first assembled in 1944 to assess the affects of the air war on Germany and later commissioned to undertake a similar study of Japan.

Nitze organized more than 4,000 men to conduct that study. The survey concluded that it would have taken at least 220 B29 bombers, fully armed with incendiary, high-explosive and anti-personnel ammunition, to equal the damage inflicted by a single aircraft armed with the atomic weapon which devastated Hiroshima.

Still, the tide of battle in the Pacific had turned at Midway and long before the two atomic blasts, the Japanese had become reconciled to defeat. In prose which retains a bone-chilling quality today, the Nitze team concluded: "Based on a detailed investigation of all the facts, and supported by the testimony of the surviving Japanese leaders involved, it is the Survey's opinion that certainly prior to 31 December 1945, and in all probability prior to 1 November 1945 Japan would have surrendered even if the atomic bombs had not been dropped, even if Russia had not entered the war and even if no invasion had been planned or contemplated."

By 1950 the Soviets had learned the secret of nuclear fission and the wartime alliance of the two super-powers had receded into memory. President Truman wanted a strategy which would serve as a blueprint for the transition from accommodation to fierce competition with the Soviet Union and justify the rearmament thought essential.

That task fell largely to Nitze, who had just succeeded George Kennan as director of the State Department's policy planning staff. With colleagues at State, Defense and the National Security Council, Nitze drafted the fabled NSC-68 Memorandum, which set the basic tone for a generation's dealings with the Kremlin.

Critics have found much in the document to deplore. NSC-68 did paint a simplistic picture of U.S.-Soviet competition, matching the forces of "freedom" and "justice" against those of "slavery." It provided at least an intellectual license for future abuses by endorsing "any measures, covert or overt, violent or nonviolent, which serve the purposes of frustrating the Kremlin design..."

The document also took a cynical view of arms control negotiations. To rally public support for rearmament, it recommended that U.S. leaders constantly put forth reasonable-sounding disarmament proposals which the Soviets were unlikely to accept. Of course, should the Russians show unexpected flexibility, "we would have to consider very seriously whether we could accept such agreements."

In NSC-68 one also sees for the first time what might be called the "clear and future danger" alert. At the time, the United States enjoyed a hefty nuclear advantage over the Soviets' 10 to 20 atomic bombs. But by 1954, it was felt, the Soviets would have 200 such bombs, half of which could be expected to reach U.S. targets. And, given the element of surprise enjoyed by a totalitarian society, 1954 could mark a turning point in our relations, unless the West responded with across-the-board military build-ups.

In defense of Nitze and the other NSC-68 authors, one must recall that the West was in fact quite weak in conventional terms during the period, that the Soviets were, and may still be, outspending us on both nuclear and conventional armaments, and that had the United States not been goaded into remobilization the Soviets may well have been able to parlay their military strength into political success. From the perspective of a nation that has overreacted to many of his warnings, Nitze may well appear unduly alarmist. But had we underreacted, there may have been no luxury of hindsight.

Throughout his career, Nitze's support of aggressive strategies and costly weapons programs, has gone hand in hand with a highly prudent attitude toward actually engaging in armed conflict. NSC-68, for example, dismissed claims that the Soviet threat justified a "preventive war" launched by the West.

Inside the Truman administration, Nitze also opposed crossing the 38th Parallel in Korea, warning it would invite Chinese intervention. Later he fought against John Foster Dulles' doctrine of "Massive Retaliation," claiming it lacked credibility, since few provocations warranted a nuclear response. He urged that Quemoy and Matsu be abandoned as indefensible through conventional means and hardly worth a nuclear war. And he was a voice of restraint in the Kennedy and Johnson administrations on Vietnam, arguing that policymakers were underestimating the effort needed to win.

Nitze had entered the Roosevelt administration in 1940 as a Republican, having switched parties in protest against FDR's efforts to pack the Supreme Court. But when he left the Eisenhower administration in 1953, it was as a Democrat again. During the campaign, Ike had infuriated him by criticizing Truman's withdrawal of U.S. troops from Korea and the Berlin Corridor, two moves Nitze says Eisenhower had privately supported.

Nitze also was irked by Eisenhower's failure to disown Sen. Joseph McCarthy's assault on Gen. Geroge C. Marshall. Recalling the two incidents today, Nitze says, "I decided I didn't want to have anything to do with those bastards. So I left."

But he had difficulty remaining a strictly private citizen. Asked frequently to speak and write on strategic questions, he was called back into more formal service in 1957, when he helped draft the Gaither Report on "Deterrence and Survival in the Nuclear Age" for the Prsident's Science Advisory Commmittee.

This report too has been criticized for its preception of an illusry "missile gap" (a term not found in the report itself), its advocacy of massive air and civil defense programs, and its recommendation that we accelerate deployment of intercontinental missiles, a proposal that produced a fantastic spurt of offensive missile production, leaving the Soviets in the dust for at least a decade.

And again there was the clear and future danger - a prognosis that while the nuclear balance was still favorable in 1957, two years later the Soviets might have 150 intercontinental missiles deployed, enough to score a decisive victory by attacking first.

Whether such exaggerated fears actually triggered the arms race of the 1960s and '70s will remain a point of conjecture for historians. Certainly they did nothing to slow it. On the other hand, the Soviets seem to have devoted a steady 13-14 percent of their GNP to military programs regardless of what we were doing, while the United States found ways to probe the frontiers of weapons technology regardless of doctrinal or budgetary constraints. Both nations seem to have been limited more by the state of the art than by the state of each other's programs.;

The limits of deterrence

But Nitze is a man of doctrine, a strategic theologian, and as the 1960s began he was increasingly troubled by the direction of arms comptetition. Both sides were amassing powerful offensive arsenals while defensive systems were either being neglected or outstripped by the offensive numbers and technology. If that trend continued, in a crisis the trigger-happy party could be rewarded with victory, since it could, by striking first, destroy the offensive potential of its adversary.

The alternative Nitze saw was to pay less attention to things like the size, speed and accuracy of warheads and to think more about dispersing large numbers of missiles, or burying them under tons of concrete, or hiding them, or making them mobile. Such a force could survive an enemy attack and would thus tend to discourage such an attack from being launched - the essence of a strategy known as "deterrence."

Critical to understanding where Nitze stands today, though, is to recall his fear in 1960 that for deterrence to work, both sides must accept the doctrine and position their forces accordingly.

The reason was not that the Soviets could achieve "some fantastic breakthrough" which would prevent us from saving enough missiles to hit them back hard. Rather, he was concerned that if the Soviet strategy was designed to win a war while the U.S. strategy was designed to prevent one from occurring, then, if war did occur, if that first nuclear shot was fired by the other side, would not the Soviets win, because the very reason for being of the entire U.S. force had simply ceased to exist? Indeed, he feared that the United States might decide not even to shoot back, since the purpose in doing so would be punitive rather than strategic.

Nitze, in 1960, did not feel conditions were ripe for successful arms control negotiations. But he did sense that the United States could perhaps initiate a process which would eventually draw the Soviets on board. In an April address to a national strategy seminar at Asilomar in California, he proposed scrapping our fixed intercontinental missiles in favor of those better able to survive attack, placing our strategic forces under NATO control and eventually inviting the U.N. General Assembly to sanction their use in a crisis.

Nitze's Asilomar remarks were accompanied by all sorts of graceful semidisclaimers, but there was little doubt then and little doday that they represented a logical and serious extension of this thinking about the nuclear arms race. They escaped the notice of his Senate interrogators when Nitze was named assistant secretary of defense for international security affairs by President Kennedy. But soon afterward his remarks were attacked by the right-wing publication, Human Events. And when, three years later, Nitze again came before the Senate Armed Services Committee upon being nominated to succeed John Connally as secretary of the Navy, he received a thorough grilling on the subject from Chairman Richard Russell, Harry Byrd Sr. and J. Strom Thurmond.

Nitze claimed repeatedly that he had not really meant what he said at Asilomar intending merely to stimulate discussion among an audience of academics. He said he really wanted the United States to press ahead with its offensive missiles. He wanted no NATO, let alone U.N., involvement in strategic decision-making.

Thirteen years later Nitze would lead the assault on the candor if not the patriotism of Paul Warnke - nominated by President Carter to head both the SALT delegation and the Arms Control and Disarmament Agency - claiming that Warnke had toughened his stance on several issues while denying any change had occurred.

The period during which Nitze served under Robert McNamara witnessed a tremendous build-up in United States strategic forces, including the development of multiple warheads fired from a single booster, each warhead capable of aiming at a different Soviet target. Largely because of this new weapon, the number of nuclear warheads in our arsenal now approaches 9,500, and the number will continue to increase regardless of what happens with SALT II.

But McNamara did stop building land-based missile launchers at just over 1,000 and nuclear submarines at 41. More important, he seemed to recognize that even without a formal arms control agreement, the two sides' capabilities had become so great as to discourage either from attacking first.

For that purpose, McNamara estimated that 200 to 400 nuclear warheads capable of surviving attack and able to hit the Soviet Union would be enough to discourage that initial attack. To many, that deterrent purpose seemed about the only thing nuclear weapons were good for.

Today, however, Nitze claims that "the McNamara Doctrine was a fraud and I thought so at the time. He changed the doctrine to fit the budget. It is highly regrettable and I continued to argue that when he was secretary. I take responsibility for my role in the decisions, but not the doctrine."

The "threat of the month"

Nitze was retained by the Nixon administration as a member of the SALT I negotiating team. Colleagues recall Nitze's value as a draftsman, particularly on the treaty sharply limiting the deployment of anti-ballistic missile (ABM) systems, and his apparent euphoria when, in May 1972, both the ABM Treaty and the five-year Interim Agreement placing numerical limits on land and submarine intercontinental missile launchers were signed in Moscow.

If anything, the ABM Treaty seemed to confirm the role for nuclear weapons outlined by McNamara. With neither side now able to deploy systems designed to knock out enemy missiles, the populations and military-industrial bases of the two superpowers were held mutually hostage. Only a lunatic would attack first, and against lunatics, there is no such thing as deterrence.

But for Nitze, another clear danger was taking shape. For one thing, he saw distrubing disparities in the strategic thinking of the two sides. Our doctrines stressed the avoidance of nuclear war while the Soviets thought more about favorable political outcomes of any nuclear scenario - threat or actual exchange.Thus the two sides come to the bargaining table with different intentions. The United States, Nitze argues, "wants to neutralize strategic arms as a factor overhanging international politics," while the Soviets want "a strategic preponderance on the basis of which they can aspire to lay down the direction of events to Soviet advantage and, step by step, to achieve eventual Soviet triumph."

Add to this aggressive Soviet posture a vast array of huge, highly destructive missiles which will - with the accuracy anticipated by 1982 - pose a threat to most of our own land-based missiles, and you have the ingredients of a tremendous Soviet political advantage.

Again, the key # fact to Nitze is that deterrence is a relative, not an absolute, concept. If the Soviets achieve an edge in the destructive power of their missile force, and if that edge would survive any potential exchange, then the Soviets have gained a theoretical war-winning capability. The resolution of past crises - Berlin, Cuba, the Middle East - reflected the nuclear balance of the two countries. In the past we prevailed or compromised. In the future we may have to back down.

To Nitze the imperative is protecting our big land-based missile force. And the way to do this, he believes, is with a defensive system known as multiple protective shelters, or MPS.

MPS would simply be a nuclear shell game played on a large scale. For a portion of our missile force, we would build not only protective shelters but several dummy missiles also housed in shelters. Since the Soveits would not know which missiles are real and which are fake, they would not know where to fire their own. To hit all of ours they would have to fire so many of their own that the exchange would not be worth it to them. After any potential exchange, we would enjoy superior destructive power. Deterrence based on American superiority would have returned.

Virtually all of Nitze's views are challenged by those who regard his thinking as more compatible with the nuclear forces of the 1950s than with today's diverse and sophisticated arsenal. Little point would be served here in reconstructing a debate which has become almost Talmudic in its scholasticism and fascination with nuance.

Yet even Nitze's arithmetic enjoys no free ride. Stewart Rubins of the Pentagon's Office of Program Analysis and Evaluation, and his boss, Russell Murray, met on several occasions last year with Nitze and his technical adviser, T. K. Jones of the Boeing Corporation, in an effort to determine why Nitze always left the Soviets with the bigger bang.

"In every case we found errors in his assumptions," Rubins recalls. "But Paul Nitze is a scrupulously honest man and he would quit using the faulty data. So he would come back a month later with the old errors corrected but a new scenario ready to go. We began calling it "The Threat of the Month." Finally we just gave up."

"More or less persuaded"

Throughout the preliminary SALT II skirmishing, Nitze seemed willing to trade his support for, or at least his non-opposition to, the treaty for a firm administration commitment to a system capable of protecting the land-based missiles. "The treaty is unacceptable if it prevents us from solving this problem," he told me, arguing that his reading of Article IV, which bans the construction of additional fixed missile launchers, would apply to the shells of his shell game plan.

But suppose his interpretation of the agreement was wrong? Suppose the treaty was interpreted as permitting MPS? Or suppose the administration came up with some alternative way of protecting our missiles which was clearly allowed by the treaty?

"Then I would say that nothing in the agreement prevents us from meeting satisfactorily our strategic requirements," he replied.

Privately, most arms controllers within the administration opposed both MPS or any other protective device based on hiding U.S. missiles. For the very essence of such a plan is deception. And deception furnishes a poor basis either for persuading the Soviets that we are living up to the treaty or - should the Soviets adopt a similar plan of their own - for persuading our own citizens that we are capable of catching the Russians if they cheat.

Nitze's plan was thus viewed by many as a formula for the disintegration of the SALT pocess rather than its evolution. So while, from the president on down, administration officials proclaimed that nothing in the SALT treaty prevented us from meeting the vulnerability problem, the administration was in no hurry to decide exactly how it wished to do so.

Politically, however, the option of delay no longer exists. Meeting over a period of months with small clusters of senators, Nitze and his colleagues have brought so many around on the vulnerability question that Carter strategists now concede that the president will have to outline with specificity his plan for protecting land-based missiles if he is to have a chance of winning SALT ratification.

At a Pentagon meeting shortly before the Vienna summit, Undersecretary of Defense William J. Perry briefed Nitze extensively on an alternative trench system designed to provide the same sort of concealed protection for missiles as Nitze's shell game plan.

"I was more or less persuaded that the system would work," Nitze told me last week, adding that the trench plan is legal under the accord.

And administration sources now indicate that the plan outlined to Nitze will in fact be the one submitted by the President.

Once again, then, Nitze's strategic views have prevailed. His notion of the clear and future danger will shape the future design of our forces. Whatever position he eventually takes on SALT II, and whatever the fate of the agreement in the Senate, competition between the two nuclear superpowers will continue pretty much as it has in the past.

In order to "beat" Paul Nitze, the Carter administration has had to join him. CAPTION: Picture, Paul H. Nitze, By James K. W. Atherton - The Washington Post; Illustration, no caption, By Geoffrey Moss for The Washington Post