ONCE AGAIN a new administration takes office and promptly offers its views on the notion that in Soviet-American relations in particular the United States should condition its policy in one area, such as strategic arms, on Soviet performance in another, say, human rights. The Nixon administration started out favoring "linkage," as it came (somewhat perjoratively) to be called. The Carter administration is starting out disfavoring it - in dealing with Moscow, that is, though evidently not in dealing with other nations, especially when human rights are involved.

Regarding the Kremlin there is "no linkage" of arms control, trade and human rights, Secretary of State Vance said the other day. A positive Soviet attitude on human rights "would certainly improve the climate, but I think there has been an overemphasis on linkage." What then would give the Russians incentive "to come along on agreements on which they would otherwise be reluctant?" he was asked. Singling out SALT as being "in the interests of both nations," he said, "I think it stands on its own two feet."

Well, the administration is young: Its pronouncements are subject to erosion. Certainly this was Mr. Nixon's experience. He attempted various Soviet-American linkages: Vietnam to trade was only the opener. But he hit at least three snags. First, the Soviets took him seriously: For what they claimed was their helpful role in Hanoi, they demanded trade - but on terms on which Mr. Nixon was unable to deliver. Second, the Congress went the President one better, setting aside Mr. Nixon's linkage (Vietnam to trade) and imposing its own (trade to emigration). Third, the various negotiating linkages got so tight and the political pressures they generated so intense, in Moscow as well as Washington, that Soviet-American business came virtually to a halt.

So Mr. Vance is right. There has been an "overemphasis on linkage." But that is not the end of the matter. Perhaps the Russians will turn out to believe, with the Secretary, that arms control is in the mutual interest. But if the Russians can achieve their SALT goals without bending on human rights, why should they bend? Will the Congress and public, not to speak of Jimmy Carter himself, accept that result? May not Mr. Vance, by denying linkage, be yielding bargaining leverage on rights? May this not double back and undercut the political support needed for SALT? One can imagine, moreover, the Russians making their own linkages. Kremlin conservatives, for instance, might wish to link SALT to a Carter retreat on rights.

Finally, although Mr. Vance did not happen to mention it the other day, the question of linkage in Soviet-American relations is very much linked, if you will, to Soviet policy in third-country political disputes. A Soviet fanning of the flames in Rhodesia, for instance, is bound to generate a political reaction in the United States quite apart from whether the administration states that linkage is or is not its chosen tactic. Linkage can be explicit or implicit, used directly in diplomacy or brought into play indirectly, but in a sense even more meaningfully, by politics. It is a tricky business that does not lend itself to catch-phrases. In short, it is not something one wants to be categorical about.