President Reagan's willingness to modify the US proposals in the strategic arms talks in Geneva - by shifting from a stress on deep reductions in missiles to controls on warheads - is a positive step. This would open the way to US deployment of a large number of new small land-based missiles with single warheads. And it might induce the Soviet Union to follow the US lead in getting away from MIRVs, the multiple warheads that have made arms control so difficult.
It is good to see fresh ideas emerging. It is also encouraging that the revised US approach, which reportedly calls for a new limit for each side of about 1,200 ICBMs rather than the 850 originally proposed, comes closer to the Soviet position. The Russians suggest an aggregate limit of 1,800 on delivery vehicles, including heavy bombers.
However, the public should be wary of concluding that this show of US flexibility offers a prospect for nudging the START negotiations any time soon. Mr. Reagan is following up on the recent Scowcroft commission report which called for precisely such a shift to warhead control. But it must be borne in mind that the commission was not trying to provide a general solution to strategic arms control but simply to the control of land-based ICBMs - the area where the US feels vulnerable.
The basic question is whether the United States is prepared to offer a comprehensive proposal which takes account of Soviet concerns and is therefore attractive to Moscow. Ballistic missiles are only one component of the strategic forces. The Russians want to know what the American attitude will be on the US strategic bombers and cruise missiles - issues the Reagan administration does not address. Under the new US proposal, the Russians would still be asked to do more than the Americans inasmuch as they would have to dismantle a large proportion of their land-based missile forces, which constitute the dominant part of their nuclear deterrence (whereas the US places more reliance on sea-based systems and bombers).
There is also the matter of the so-called forward based systems - such as the nuclear weapons on US carriers in the Mediterranean - which the Russians regard as strategic. In other words, there remains an enormous gulf between the two sides, and a long way to go before the obstacles are surmounted.