President Reagan is in that difficult place with the Russians where he is struggling to match his beliefs to his interests. His beliefs, which are also in some measure his and others' perceptions, tell him the Russians lie, cheat and steal, and that arms control is therefore a dubious proposition. But his responsibilities as president and his position as a political leader require him at the least to make a good show of pursuing arms control. This is what the current pulling and hauling over verification is about.

Knowing well the president's disposition, the know-nothings have collected a mixed bag of alleged Soviet arms control violations, and they are hounding him to denounce the Kremlin or otherwise react in a way that would effectively scuttle the continuing negotiations. More sensible folk, however, have also gotten into the argument, and as a result Reagan is squirming rather than yielding: he has set up an interagency committee to gain himself some control over this volatile issue, and he has indicated that if and when he reacts, it will be first within the discreet channels set up to handle this sort of thing.

The difficulty is that he has clogged the principal such channel, the Standing Consultative Commission, the experts' forum that Soviets and Americans have used for 10 years to work out detailed rules and procedures for ensuring compliance with arms control agreements. From what one hears from both sides, the record of the SCC is perfect: every practice questioned in it by either Moscow or Washington has been ended or explained. The new Carnegie Endowment arms control report, chaired by William Hyland, calls the SCC "remarkable."

Reagan, however, has all but barred his own way to using the SCC in the most politically sensitive realm, compliance with the SALT II agreement. The word at the White House is that to use the SCC to police a treaty that the administration continues to regard as unworthy of ratification, even while it pledges not to undermine its terms, would legitimize SALT II more than Reagan would like. So it was that the administration waited 20 months, until last October, to raise its first and so far apparently only SALT II question (about SS16s) in the SCC.

The hottest current SALT II verification question, however, seems not to have been taken to the SCC. Was the missile that the Kremlin tested last Feb. 8 a permissible modification of an existing light ICBM or a banned second new ICBM? This is precisely the sort of difficult, fine-grained interpretive question on which the SCC has earned its credentials for unpolemical quality analysis. The administration is pursuing the Feb. 8 matter but not through the SCC. That's like coming to the fine print and taking off your glasses.

To be sure, there are other difficulties. The strong evidence of Soviet violations of the biological and chemical warfare treaties has created a general crisis of verification. "Yellow rain" and the Sverdlovsk incident have put arms control advocates on the defensive intellectually as well as politically, imposing on them an extra burden to prove the American interest will not suffer from Soviet violations of nuclear arms control accords.

Our most prominent advocate of arms control is, of course, Reagan, the role being thrust upon him by the fact that he is necessarily the custodian of past agreements and a negotiator of prospective new ones. The president, notwithstanding his hangup on the SCC, shows some signs of filling the part. As indicated, he has rebuffed his conservative friends' call to leap on the Soviets before he looks into the violations attributed to them. He warns the public that "courtroom evidence" is hard to come by. He is saying, bravely, that any treaties he makes won't be ambiguous--"the clauses that are in there are hard and fast."

He should check out that new Hyland report, whose signatories include some hard-line heavies. "Adequate" verifiability, it points out, means not only detecting violations that could hurt us but being ready (by R&D "hedges") to compensate quickly. It says that while yellow rain requires a raising of the standards of verification, the methods have gotten better thanks to new technology, refinement of procedures like the SCC, and the experience of the intelligence community.

"Doubts about verification, while of growing political importance, should not obstruct the negotiation of viable arms control agreements that are in the national interest," the report concludes.