"WE WOULD have been better off with the bubonic plague."

The speaker was Adm. Thomas Moorer, a former chairman of the Joint Chiefs of Staff and one of the crustiest "hawks" who ever came out of the Navy. He was talking about the man he loves to hate, Robert S. McNamara, who, as secretary of defense for most of the 1960's, overhauled the Pentagon and managed U.S. forces in Vietnam.

McNamara is not the only defense secretary to inspire strong emotions in defense circles. Caspar W. Weinberger, who recently vacated the top defense post is equally controversial, though for almost diametrically opposite reasons. Comparing these two men, our longest-serving and best known defense secretaries, raises important questions for the current incumbent, Frank Carlucci and for the next administration: Must we base defense policy on the fights of 20 years ago? Have we learned nothing about civilian-military relations? How can we get the most bang for the defense buck? How much is enough defense spending? As future defense secretaries try to answer these questions, they will do well to combine the positive lessons of McNamara and Weinberger's approaches rather than bogging down in the essentially negative debate over the two men that still consumes many in the defense community.

Weinberger and McNamara share important traits. Both are highly intelligent, well-read, formidable debaters. Both are experienced public administrators. Each is gracious at close range; each is loyal to his team of subordinates.

Both, moreover, seem driven to cast themselves as actors on an ideological stage. They transformed their fights with Congress over budgets, hardware, or the Soviet threat into universal questions: what kind of country, what kind of world do we want? Which is why the presidents they served valued them so much. And why each man arouses such violent, personal emotions on the left and right.

McNamara and Weinberger's styles, however, were worlds apart. "The perfessor," as President Lyndon Johnson dubbed McNamara, had taught business at Harvard and rose to the presidency of Ford Motor Co. in 1960 on the strength of his iron control over and detailed knowledge of the company. As defense secretary he assumed similar control: "I don't need any hatchet man" he told the Congress early on. The joke was he knew the contents of all the drawers in the supply room at Fort Dix.

Weinberger's style runs so counter to McNamara's that I have often suspected he was consciously setting himself up as McNamara's antithesis. "I guess you could say that he was trying to undo a lot of what McNamara did" admits former Weinberger spokesman Robert Sims.

Weinberger functioned as chief salesman for the military establishment. He stayed with general arguments, and seemed uninterested in the details of budget or strategy. His background was law and journalism, including eight years as a talk show host. His impassioned advocacy could be very successful though it could leave his audience "more entertained than appalled . . . like adults listening to the tall tales of a precocious . . . child," as columnist Edwin Yoder recently wrote.

This contrast in styles translated into starkly different approaches to almost every policy area. Here are examples from three areas: budget, procurement and foreign intervention and management of combat forces.

The budget. McNamara came to a Pentagon rife with interservice strife. He also came to work for a President, John F. Kennedy, who had promised to get America moving again in defense.

In 1961 McNamara introduced a Rand Corporation invention later known as the Planning Programming and Budgeting System, or PPBS. Hailed initially by Congress, the press and many in the military, the system broke down all defense activities into "program elements," each with a current price tag and five-year projection, grouped them by function into program packages (Polaris missiles, were part of stategic retaliatory forces, for example) and measured their effectiveness (e.g., how many bombs delivered on target per unit cost).

Guided by PPBS findings of overlap and inefficiency, and aided by a then-little known group of "systems analysts," McNamara slashed away at the force structure. He cut the Air Force's prized strategic bomber force, challenged the powerful Hyman Rickover who wanted more nuclear-powered aircraft carriers, stopped the Army's preferred rifle, the M-14, in favor of a "popgun," the M-16. McNamara's men, stubbornly insisting they had built a "rational" defense policy, would concede nothing to politics or tradition.

The impact of McNamara's centralization of decisionmaking is hard to overstate: PPBS, much refined and enlarged, is still the basic decisionmaking procedure for our military establishment and systems analysis is now a thriving industry in and out of government.

Weinberger took the opposite approach to the defense budget. Ten days after taking office in 1981, he sat down with budget director David Stockman and drew up a one-page "treaty" giving defense $33 billion more in fiscal 1981 and 1982 than the $20 billion increase already sought by President Carter. Many Pentagon experts were flabbergasted by the increases, but the services dutifully recommended programs to reach the new ceiling. Weinberger essentially stapled these requests together and took the whole thing to Congress. His debating skills -- along with Reagan's legislative magic -- won a 50 percent budget increase -- on top of inflation adjustments -- over only four years, helping to puff up the federal deficit to its current perilous level.

So effective was Weinberger's salesmanship that, since 1985, even after adjusting for inflation, defense budget authority has been as high or higher than it was at the peak of the Vietnam War! But the force that Weinberger bought for $315 billion in fiscal 1985, for example, was much smaller than that McNamara bought in 1968 for $280 billion (in comparable dollars), a fact that says much about their different approaches to buying weapons.

Procurement. McNamara's analysts posed the now-famous question "how much is enough?" in pressing to obtain the most military power at least cost. They also campaigned for simpler, cheaper weapons so as to be able to buy more -- displacing the M14 rifle by the M16, for example, stopping the B70 bomber to get more strategic power through ICBMs, or foregoing nuclear propulsion to afford more ships.

But McNamara and his planners were accused of deliberately endangering pilots or soldiers through their obsession with cost. "Those of us who learned the hard way . . . attach great significance to what might otherwise appear inconsequential differences between two competing pieces of military hardware," thundered another angry admiral, George W. Anderson, at 1963 hearings on the McNamara-imposed Air Force-Navy fighter, TFX. Moorer told me what he did with the Navy version, "I sabotaged it."

McNamara argued he could get more fighting power with less money: and the later backlash obscures the fact that in his first years at the Pentagon he was seen as a man who delivered technology and made it work.

To Weinberger, however, more spending equalled more strength. And by decentralizing and giving responsibility for hardware choices to the services, he built service morale. No one can accuse him of not buying "the best" -- the most capable weapons. He also succeeded in bringing in weapons at close to their originally projected cost. Those costs, however, were very high so that, even with a much bigger budget, many fewer weapons could be purchased.

The Congressional Budget Office, comparing Weinberger's years with the previous seven, found that we bought, for example, 8 percent more combat aircraft, but spent 59 percent more to buy them, 79 percent more rotary aircraft, but at more than four times the previous cost.

Moreover, Weinberger's expensive forces have been found embarassingly unready or unsuitable on occasion, as, for example, in the Persian Gulf where powerful U.S. ships wallowed helplessly, stymied for lack of humble minesweepers. I told you so, sniffs the McNamara camp from the sidelines. You can't trust the Navy to put the national interest before the Navy's interest. We fought that one long ago.

Nuclear weapons and strategy. Weinberger used the same decentralized approach to buying strategic weapons: he continued the new superaccurate MX missile, (in two basing modes), agreed to add the mobile Midgetman, revived the B-1 bomber (while continuing the Stealth) and built a 2,000 cruise missile force. He was not consulted in advance about Reagan's "Star Wars" proposal made in March 1983, but within days he had become one of its principal advocates.

In sharp contrast, McNamara believed the secretary should be the preeminent strategist on nuclear matters. McNamara's strategic record is mixed: after considering other approaches he installed "mutual assured destruction" as the dominant stabilizing strategy of the nuclear age. But he also approved a "thin" ABM system and the "MIRV" (multiple-warhead) guidance technology knowing that both had the potential to upset the stability created by mutually threatening offensive forces. He tried to get the Soviets to limit their ICBM deployments but they built up instead. McNamara-haters argue that by capping U.S. ICBMs, and failing to restrain the Soviets, he gave away U.S. security.

Military intervention. Weinberger's critics call him dangerous for saying we should "prevail" in a nuclear war, building up nuclear forces, pushing Star Wars, and opposing arms control. But they cannot deny that in 1982 and 1983 when military intervention in Central America was discussed by the President, Weinberger, fearing another Vietnam and backed by the Army's Chief of Staff, advised against intervention. Moreover, when the military did intervene, Weinberger deliberately stayed away from operational details.

By contrast, McNamara's activism, his belief in his powers of control, made him advocate escalating military commitment to Vietnam. Then, having become the leader of men at war, McNamara tried to control them. That is really why Moorer and other military men are so bitter about McNamara. He sent the forces -- those he had made so ready, so well-armed, so well-supported -- into a war. And then he presumed to tell them how to fight it, once again countering military preference and tradition with his "facts," his endless argument, his seemingly unlimited power.

So the military got no callup of the reserves, fewer ground troops, fewer bomb sorties, than they wanted. Later they had to swallow the electronic "McNamara line" as a substitute for widening the bombing as they wished. McNamara had forced on them programs they didn't want. Now he eroded their power to do their ultimate -- and most emotionally taxing task -- the task of making war.

If it had worked, the history books would have been different. But when the secretary of defense is issuing orders specifying the bombs and missiles that pilots can drop on Asia bridges -- and the bombing doesn't produce results -- he becomes the target.

Hunched in the witness chair with his feet hooked around the chairlegs, the thick briefing books filled with numbers beside him, testifying by the hour on every detail of the defense program, the war, McNamara became a symbol of the failure of the age, his numbers so obviously unable to describe the tragedy which unfolded around him.

Of all the questions the McNamara-Weinberger contrast raises, this question -- the proper role of the secretary of defense in managing a war -- is the most emotional, least examined, and most troubling for the future. Where, in war -- and in peace for that matter -- does civilian control and military accountability leave off and meddlesome interference in military matters begin?

One way to approach these questions is to continue to fight old battles over past mistakes: But backlash from past mistakes makes bad public policy. And the problems of today are urgent, as Frank Carlucci, Weinberger's successor has apparently recognized even in his first weeks in office.

Far better to look to the positive aspects of the record. As McNamara did in 1963-65, future secretaries will have level or declining defense budgets within which to find ways to get more bang for the buck. Like Weinberger, they will face the realities of powerful Soviet conventional and nuclear offensive forces and a Soviet "Star Wars" system. The military may be targets of "backlash" -- as in the early 1970s, and the secretary will have to boost morale -- as Weinberger did. The economic and consequences of defense spending -- on which both men did poorly -- will be crucial. These are constructive lessons that a new secretary can learn from these two, if he is willing.

Deborah Shapley's book on Robert S. McNamara will be published later this year.