There distinctly is a change, and a welcome one, in the atmosphere of US-Soviet relations. A new five-year grain deal, talk of new US proposals in the strategic arms negotiations in Geneva, and some conciliatory gestures from Yuri Andropov are all part of what looks to be a growing momentum for a summit meeting next year. President Reagan, with his eye on the 1984 election, plainly is trying to resolve the early image of pugnacious hawk into one of peacemaker and statesman.
It is in this context that the persisting US concern about possible Soviet cheating on arms agreements should be viewed. The United States, according to the New York Times, has called for a special meeting of the joint Standing Consultative Commission, the forum which considers questions of compliance with the SALT treaties. To what extent the move is prompted by pressures from conservative forces in the Senate and the Pentagon is not clear. But it is clear that Mr. Reagan is being careful not to accuse the Russians of skullduggery without solid proof.
Three issues are involved: the Soviet testing of a new intercontinental missile that could be a violation of the unratified SALT II treaty; discovery of a new radar system in central Siberia that could violate the 1972 ABM treaty; and possible installation of an SS-16 missile system around Plesetsk.
Ambiguities surround the issues. In the case of the new ICBM, the so-called PL-5, some American officials suspect this may be the second new missile being tested under a treaty which permits development of only one. But the Russians claim that it is merely a modified version of a smaller missile already in their arsenal (modifications are permitted under SALT II). The US data on the missile tests seem to be inconclusive, however.
Radar systems, for their part, appear to be a growing technical problem for both sides because of the ABM treaty. There are differ
ences between warning radars and radars that can be used to guide antiballistic missiles. Under the treaty each side is permitted to have only one ABM system and the Russians have theirs deployed around Moscow. Are the radars detected in Siberia a second ABM system as some in the Senate believe? Or are the Russians merely testing the radars - which would not be illegal? American arms control experts say the US, too, has installed new radars which may in turn be bothering the Russians.
Of course the two sides ought to get to the bottom of these and other concerns. Charges about Soviet violations have persisted for years. But even if they frequently come from hawkish US elements that oppose arms control - and may therefore be suspect - they can mar the negotiating climate if not thoroughly dealt with. Americans need to be reassured that Moscow is a reliable arms control partner and that, while it stretches any accord to its outer limit (as does the United States) and sometimes is caught in minor infractions (which it then corrects), it does not go so far as to flagrantly violate agreements.
In any case, the US is turning to the proper forum to find the answers. In the beginning the Reagan administration had avoided taking up SALT II questions in the SCC for fear of lending stature to an unratified treaty which it did not like. But times are changing. Moscow and Washington now want it perceived that they are abiding by the provisions of the pact even as they engage in hard bargaining for a new agreement.
In short, Mr. Reagan has visibly toned down his public rhetoric and is trying to convey that his administration is serious about stopping the decline in relations with Moscow. Naturally he must respond to charges that the Russians are cheating on arms agreements. But the fact that he is taking the route of quiet, behind-closed-doors diplomacy instead of public accusation is cause for satisfaction.