The two freezes

The recent proposals for freezes of nuclear weapons - by Senators Kennedy and Hatfield and by President Brezhnev - tell us more about the politics of arms control than about how to achieve it.

The Kennedy-Hatfield resolution picks up the grass-roots campaign for the same purpose. In essence, it calls for the United States and USSR to agree on a ''verifiable freeze on the testing, production and further development of nuclear warheads, missiles and other delivery systems,'' to be followed by major negotiated reductions, ''in a manner that enhances stability.''

Senator Hatfield calls the freeze ''simple and practical.'' Critics brand it simplistic. Such a freeze could not be verified without the kinds of inspection firmly rejected by the USSR up to now. It would leave the Soviets with their most destabilizing weapons and block US efforts to counter them. It would thereby undercut Soviet incentives for further negotiations for reduction and control.

Despite this, the resolution is cosponsored by 150 members of Congress and endorsed by a long list of distinguished individuals. Why? Doubtless many do not view the freeze as a concrete measure for adoption. Frustrated and concerned by the attitude of the administration toward nuclear weapons and arms control, they see it as a simple and appealing idea for rallying public opinion to put pressure on the President.

One can share their concern without embracing their means. The administration can almost certainly defuse much of this movement by coming forward promptly with serious proposals for arms control. But if they are designed, as they should be and as the resolution urges, really to enhance stability, they will not be simple or easy to achieve.

The gravest threat to stability is the trend toward counterforce capability. That is the most disturbing aspect of the Soviet SS-17, 18 and 19 ICBMs which combine 4 to 10 powerful warheads with accuracy sufficient to destroy most of the US ICBMs. And the MX missile would have the same characteristics. The eventual result could be to put both strategic nuclear arsenals on the hair-trigger of ''launch-on-warning'' to avoid being wiped out by a first strike. Nothing could be more dangerous.

A primary aim of arms control should be to reverse this trend in order to enhance stability. Unfortunately neither SALT I nor SALT II served that objective, as Senator Hatfield himself has stressed. As Joseph Krusel argued on this page last week, each side must be encouraged to move away from vulnerable, fixed, land-based MIRVed missiles. The balance would be much more stable if both sides had smaller, mobile missiles with single warheads, or more of their missiles at sea. An agreement which caused each side to reshape its strategic arsenal in this direction by stages over the coming decade would reduce vulnerability on both sides and enhance their real security.

Would the Soviets even consider such an approach? The signs are not encouraging. It would require radical changes in Soviet concepts as well as in their weapons systems. In 1977 they flatly rejected the Carter proposals for sharp cuts as one-sided, but made no counterproposals, and insisted on returning to the limited Vladivostok formulas. Moreover such an agreement would inevitably require forms of cooperative or intrusive verification going well beyond what the Soviets have thus far accepted. But that will probably be necessary anyhow for arms control in an era of cruise missiles.

Arms control of this sort will not be conceivable unless and until both sides are really convinced that strategic nuclear weapons are useful only to deter their use by the other side and can create serious threats to their security unless brought under control.

Mr. Brezhnev's conditional effort to freeze deployment of SS-20s in Europe is hardly a hopeful sign. It was coupled with the threat of further deployments and of retaliatory measures in kind against the US, if it should prepare to deploy Pershings and cruise missiles. With some 300 SS-20s already in place this initiative is a bald attempt to exploit West European and especially German concerns in order to perpetuate this 300 to 0 advantage in such missiles. That hardly suggests a serious Soviet interest in working out a stable balance in Europe at the Geneva talks.

The US should not, however, allow doubts about the Soviet reaction to deflect it from making proposals for reductions and restraints which would enhance stability and reduce the risks of war by mistake. In the next few years, the Soviet leadership will be shifting to a new generation. We do not know their outlook or priorities. But in a period of economic strain, they may be interested in serious arms control. The US should be making it clear that such an option is available.

The conduct of productive negotations, however, will take patience and time. Commenting on the freeze proposals, Roger Molander, who now heads the Ground Zero effort to educate the public about the dangers of nuclear war, has said: ''Arms control is complex. It's not good to encourage people to think that nuclear holocaust can be avoided by simple technical fixes.'' If the freeze movement does generate hopes and demands for quick results, it could be an obstacle to constructive agreements and could defeat its own purposes.