Is the MX necessary?

It was prudent of Defense Secretary Weinberger to order a review of the vast MX strategic weapons project evenw hile allowing for continued development funds in the Pentagon budget. During the presidential campaign Ronald Reagan seemed doubtful about the way the MX (missile experimental) was to be trundled around a complex series of shelters in the West. Pentagon officials have said that the results of Mr. Weinberger's review could range from cancellation of the plan to a revised form of deployment to final acceptance of the present scheme.

Meanwhile, every new estimae of the system's cost is higher than the last. And resistance to it grows in Utah and Nevada, the states designated to absorb this largest construction project in the world, its more than 100,000 builders and operators, and its impact on the land, water, and society of the region.

The questionis whether the strategic military assets of the plan are sufficient to outweigh the political, social and environmental problems. In calling for a review, Secretary Weinberger went so far as to imagine "a separate lawsuit over each silo." (Each missile would move among 23 silos or hardened missile shelters in each of 200 loops for a total of 4,600 shelters.) Legal objections might be raised, for example, on whether the mandatory environmental impact staement paid adequate consideration to alternative sites and methods of deployment -- such as the leading contender, the submarine-based SUM (Shallow Underwater Missile System). Special legislation, as in the case of the Alaska pipeline, might limit litigation. But further potential delay is inherent in the legislative process for releasing thousands of square miles of public land for te project.

The Carter administration came out for the MX as part of the bargaining for SALT II ratification. What the Weinberger review needs to determine is what form of MX, if any, is actually necessary for America's defense.

The currently proposed MX array is defended as providing "pre-launch survivability" for US land-based missiles. The theory is that the Russians would have to launch missiles with enough warheads to hit 4,600 shelters to be sure of hitting the 200 missiles (each with 10 independently targetable warheads) hidden in them. Ironically, the effectiveness of this theory depends on SALT II limits that would prevent the Russians from using enough warheads to mount such a barrage. Without SALT the Russians could proceed unchecked.

Even the SALT they could hardly be expected not to escalate the arms race by building a mobile missile system of their own in response to the MX deployment of 2,000 warheads threatening the land-based missiles on which Moscow, unlike Washington, places its principal reliance. Seventy-five percent of Soviet warheads are land-based, compared to 24 percent in the US. Fifty percent of America's are on submarines, compared to 20 percent for the Russians. Twenty-six percent of America's are on bombers, compared to 5 percent for the Russians.

Such differences -- along with variations in matters like payloads, accuracy, ability to hit hardened targets quickly -- have to be considered in judging the net capacities of one side as against the other. Ideally the present overall rough equivalence would be frozen through agreed arms limitations and then cut back on both sides in the genuine arms reduction President Reagan calls for. Indeed, one of the valuable proposals discussed in the SALT negotiations was a moratorium on new land-based missiles. Secretary Weinberger's review must consider whether the US should forgo the possibility of accepting such a moratorium by becoming irrevocably committed to the MX array.

If it is found that increased "pre-launch survivability" is quickly needed, there are deceptive deployment systems that could go into operation faster by using existing Minuteman missiles instead of waiting for the larger MX (roughly equivalent to the Soviet Union's SS-19, the biggest permissible "light" ICBM -- intercontinental ballistic missile -- under SALT). For example, a land-based system once favored by the Air Force would have used many vertical silos with missiles shifted among them as in a shell game.

Among other means of deployment are the aforementioned SUM, a fleet of small submarines in US-controlled continental shelf waters; a number of surface ships at sea; or perhaps 200 short-takeoff-and-landing airplanes scattered among major airports and ready to whisk their airborne ICBMs to any of thousands of other locations when given warning of attack. The Air Force claims to have studied all the options before settling on the present plan. But, with so much at stake , one more look won't be wasted.

The sea-based plans could have environmental and cost advantages, and they would remove a prime Soviet target from the continental United States. But they run into a key strategic concept that the US has not been disposed to abandon despite some contrary analyses. This is continued reliance on land- based ICBMs as part of the land-air-submamarine defense "triad" even though the less vulnerable submarines alone (already carrying 50 percent of US warheads) would theoretically be sufficient for the massive retaliation calculated to deter a first strike by Moscow. Some MX proponents speak of an intangible sense of sovereignty helping to dictate deployment on the land and physically within national borders. There is also the presumed greater accuracy of launching missiles from a land base, though advances in satellite navigation technology are helping to increase accuracy from any point.

Obviously there are enough pros and cons to require that the Weinberger review be thorough and dispassionate .

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