As the great bam and crasg of the 1977 arms-control debate gets under way, Secretary of Defense Harold Brown sits serenely in his Pentagon office - somehow outside the critics' range of fire. The riddled frame of Paul Warnke, looking like Fearless Fosdick on a particularly bad day, has barely survived the Senate's discussion of his fitness to be chief arms negotiator with the Russians. Charges of weakness and fuzzy-mindedness of the one side have been met with charges of saber-rattling and nuclear adventurism on the other, requiring the intervention of the President himself. And there, in the midst of it, unscathed, unnoticed and slightly out of public focus, is Brown. What makes the situation so odd is that Brown probably the most important administration figure in the arms-control drama that is about to unfold.

The point is this: if Harold Brown seriously objects to a proposed U.S. negotiating position, that will likely be enough to kill it. And if he objects to a treaty the administration brings home, that would be enough to stop the Senate from ratifying it. It is true, of course, that administrations have always worried that the Pentagon would go over the side on arms agreements and that they have been bargained lavishly with our own military to keep this from happening. But Brown is in a uniquely strong position. There is a sharp dispute within the political community about the meaning of the Soviet arms buildup, and there is much anxiety among military-minded Democrats that Carter has stocked the national-security pond of his government with too many detente-minded fish. One cry for help from Harold Brown is all it would take to deal the administration's policy to lethal-blow.

The interesting question is what it would take to provoke such a cry. Brown is generally regarded by the so-called "hard-liners" in Washington as the closest thing they have to a soul mate in the upper reaches of the administration. But that is not very close and they know it. For Brown is no doctrinaire advocate of the military's interests or of the buy-more-build-more school of defense. On the contrary, he is notoriously well educated in the intracacies of strategic-arms policy ' and even more notoriously independent. A physicist by training, he has spent two decades near the center of the nuclear decision-making process: as an arms-control adviser, a rising star at Edward Teller's Livermore Laboratory, head of defense engineering and research in McNamara's Pentagon, Secretary of the Air Force under Johnson and SALT delegation adviser in the Nixon-Ford years. In the course of all this he has acquired a reputation for brilliance and political detachment that contributes to his importance now: every faction wants him - in fact, needs him - on its side.

I was struck, in taliking to half a dozen people who occupy different positions on the arms-control roost, by the respect in which Brown is held. Often it is the only thing they have in common - a regard for his mastery of the subject and his intellectual straightness. It is astonishing when you consider it. Over 20 years, Brown has certainly been associated with weapons policies and Vietnam activities that were anathema to liberals, and yet some of the most important of them in Washington consider him a prospective ally and friend. Likewise, this onetime "whize kid," part of the group that so offended the military by its alleged brashness and insensitivity in the 1960s. enjoys famously good relations with much of the brass.

People say that when Brown became Air Force Secretary, the officers and civilians in his charge soon learned two things about him. The first was that he was no one to take on in an argument if you didn't have an airtight case. The second was that he was a hell of an advocate of your view - and the Air Force's - if you could persuade him. No less a figure than Maj. Gen. George J. Keegan Jr., the retired head of Air Force intelligence, who has been sounding the sharpest alarms about the Soviet buildup and what he regards as the dereliction of the U.S. response, went out of his way to indicate his respect for Brown in a luncheon speech the other day, despite their differences. When I later asked Brown what he thought accounted for this relatively blessed position he held among people who might abominate some of his works, he said he thought it was his willingness to "look at subjects on a rational and dispassionate basis - I can be influenced by facts."

The facts - ever the scientist, Brown speaks habitually and almost reverentially of them. When you engage him in a discussion of familiar strategic issues and the big Miss Clairol questions concerning the Soviets - i.e., do they or don't they subscirbe to our own doctrines of deterrence and the "unwinnability" of nuclear war ' he will muse for a bit on the ambivalence of some of their literature and the swings back and forth in their statements of doctrine and then come back to this: "But I believe the facts will prevail - whatever the doctrine asserts."

The facts Harold Brown believes to be the relevant and controlling ones begin with his belief that nuclear war can neither be limited nor won if it is fought. It will result in "the total destruction of both sides." He does not think, at these levels of nuclear armament, either side can acquire a war-winning advantage over the other, or a weapon that cannot be encountered. And he does not think that we or the Russians are buying increased security with increased numbers of nuclear weapons. At the same time, Brown takes a very dim view of the Russians' pursuit of ever bigger and more menacing missiles and of their apparent efforts to seize some advantage. He believes that it could tempt them to adventures that might in turn provoke nuclear war and that for this reason the U.S. must either get a new arms agreement - or move ahead with weapons that can neutralize theirs.

Brown's first choice is clearly a new agreement. But he is serious about the alternative, and he regards the forthcoming exploration of the Soviet position by Secretary Vance as a critical exercise, one that will indicate which way the U.S. is likely to have to move. This position separates him from those arms controllers who think the Soviet buildup is a giment of the military's imagination and those on the right who believe the obly fit response is a matching of Soviet weaponry item by item.

Some people in the Pentagon have worried that Brown "is not nervous enough about the Russians," as one put it, adding: "It takes more to trip his wire than it did Laird's or Schlesinger's." Precisely because that is true, Brown's insistence that the moment has come to respond to the Soviet moves if arms-control measures cannot be achieved has added force. He will have his representatives on the Vance-Warneke Moscow mission. For all of them it will be a kind of nuclear high noon.

Reprinted with permission from Newsweek