Mobile Missile Debate Heating Up. US STRATEGIC DETERRENT. Midgetman backers battle MX boosters toward compromise version of nuclear shell game

EARLY this spring Congress, the Pentagon, and President Bush will together decide what the United States arsenal of land-based nuclear missiles should look like in the year 2000. It could be one of the most important national security choices made in Washington this year. At issue is something politicians have argued about off and on for decades: how to ensure that US land missiles can survive a preemptive Soviet attack.

In today's age of precision guidance systems ICBMs stuck in fixed silos are widely considered nothing but sitting ducks. The answer, almost all experts agree, is to take the missiles out of the ground and move them around in a sort of nuclear shell game.

The problem is how to provide this movement - or more precisely, how much the US can afford to pay for it. ``It's very important that we add that element of mobility to our land-based force,'' Defense Secretary Dick Cheney said last week in his first press conference.

As often happens with nuclear weapons, the candidate systems are called by names that seem designed to play down their destructive capability.

The first is MX, which is in fact not a gasoline additive but a 10-warhead ICBM that is already in production. Fifty MXs have now been deployed in old Minuteman silos in southeast Wyoming.

The Air Force has proposed taking MXs and putting them on railroad cars. Remaining on Western bases most of the time, these missiles would be flushed onto the nation's rail lines in times of tension.

The advantage of this approach is that with 10 warheads and a warm production line it is the most cost-effective choice. Its disadvantage is that the mobility of these large rail-mobile missiles would be limited.

The second choice is ``Midgetman,'' a one-warhead weapon that some observers grumble sounds like a circus act. Now on hold in the advanced development stage, Midgetman would be shuttled around Air Force bases on its own armored, turtle-like truck.

This small, wheeled weapon would be far more mobile than the MX alternative. But it would also be much more expensive. A 500 warhead Midgetman force would cost about $36 billion to 39 billion, according to Air Force estimates. The same number of rail-mobile MX warheads would cost about $12 billion.

Politics, of course, has complicated the choice between these alternatives. The MX is supported by most Republicans and many officials in the Pentagon, while Midgetman is widely seen as a Democratic-supported missile that enjoys only lukewarm Air Force support.

The decision will likely not be an either-or one. Air Force Chief of Staff Larry Welch has already traveled to Capitol Hill to discuss various compromise options with key members of Congress.

When new Pentagon chief Cheney heard about these preliminary discussions, he blasted General Welch, saying he was ``free-lancing.'' Air Force officials insist that Welch was not usurping the secretary's prerogatives.

``It was just a case of providing information,'' says one.

One option discussed would involve taking the 50 existing MX missiles out of their silos and placing them on rail cars, and then building a force of 300 Midgetmen.

A number of congressional Democrats call this approach promising. They say it recognizes the political reality that Congress will not approve production of further MXs beyond the 50 now deployed.

``That's just not in the cards,'' says Rep. Les Aspin, the Democratic chairman of the House Armed Services Committee.

Whether the Air Force has really accepted that limit, however, is not yet clear. An Air Force statement released last week repeats that ``an additional 50 MXs'' would be much cheaper warhead for warhead than Midgetman.

Representative Aspin insists the US needs the sort of mobility Midgetman would provide. A rail-mobile MX force, he says, would require several hours of strategic warning time to warm up the trains and safely disperse onto public track. Midgetman trucks, by contrast, would be constantly in motion on bases and require little if any warning time to scatter.

The US probably would have several hours warning of Soviet intentions in a nuclear crisis, Aspin admits. But receiving a warning is not the same as acting on it. In 1973, for instance, Israel had many hints that Egypt was about to attack, but Israeli leaders misjudged them and were caught unprepared.

``Warning indicators can be ambiguous,'' says Aspin.

Fred Ikle, undersecretary of defense for policy from 1981 to 1987, replies that Midgetman would still be a waste of tens of billions of dollars. The reason, Mr. Ikle says, is that as submarine missiles and cruise missiles proliferate and become more accurate, their land-based brethren are simply becoming obsolete. If the US has strong sea-based and bomber nuclear forces, why bother spending huge sums of money to ensure ICBM survivability?

``They are getting almost as outmoded as horse cavalry were at the beginning of the Second World War,'' says Ikle.

Fifty rail-mobile MXs would be useful as a limited addition to US deterrent strength through the turn of the century, Ikle judges. Midgetman, on the other hand, would not be ready to be deployed until around the year 2000.

As part of its ongoing budget review the Pentagon will decide sometime in early April which missile option it prefers. This choice will be ratified, or changed, by President Bush, and then negotiations with Congress will begin. The outcome will be set in law as part of the defense budget bill to be passed later this year.

One factor that could further complicate the decision is the Strategic Defense Initiative. SDI supporters say that even a limited strategic defense could improve the survivability of land-based missiles, by ensuring that not all attacking weapons would find their targets.

``As we look at improving our deterrent capability, we also have to look at SDI,'' Defense Secretary Cheney said last week.