My fantasy is that President Reagan will solve the MX problem by an extraordinary perceptual breakthrough, one uniquely available to him as a strong, radical and, now, battle-tested conservative. The breakthrough would be to decide that there is no MX problem, or rather that the problem that the MX is meant to solve--the vulnerability of the United States' 1,000 land-based Minuteman missiles, the chief part of the American nuclear deterrent--isn't that dire after all.

I am fantasizing, but I am not kidding. Look at where we are now in the MX debate that began years ago when people started thinking that Soviet advances in multiple warheads and missile accuracy might eventually give the Kremlin a capacity to destroy our land-based missiles in a first strike. The very thought that Moscow might be tempted to threaten or do this in a crisis, requiring us either to preempt or to cave in, was enough to send us, shuddering, to the drawing boards.

Dozens of drafts later, where are we? Each of the proposed solutions--land-based MXs in the western desert, air-based missiles in transport planes, and all the variations--has immense liabilities. Any solution finally reached will leave even its warmest sponsors dismayed.

That is why something popped in my mind when I read in Mike Getler's story of last Tuesday that the Townes panel set up by the Pentagon to study MX-basing alternatives--surely no dovecote--had not stopped, or started, there. Rather, it had gone back to basics and asked whether the Minuteman force that the MX is meant to supplement is actually vulnerable.

The panel's findings are not yet a part of the public record. I note, however, that there are a number of considerations, more or less familiar even to lay students of the MX question, suggesting that our Minuteman force is not so greatly vulnerable that strenuous remedies are required.

Technically and theoretically, yes, our missiles might be overwhelmed by a Soviet first strike, and this technical and theoretical prospect is not without its own political dynamic.

But to launch an attack the Soviets would have to figure that their missiles, which have never been fired in anger, would work according to peacetime plan. They would have to figure that the United States would not fire back either before or after Soviet missiles landed, and that they could withstand an American counter-strike to boot.

All these figurings: they underline that Minuteman vulnerability is not so much a technical or even a political question as a psychological or anthropological one. Any serious answer to it is inevitably and properly going to arise from a very subjective judgment of one's own nerves and psyche and culture, and the other fellow's.

We are accustomed to thinking of the president as the chief national strategist. Perhaps we should also be thinking of him as the chief national shrink, one who accepts that some of our security anxieties are prudent, healthy and reasonable but that some of them stir in the realm of the irrational. The widespread fear of Minuteman vulnerability, I would contend, is in that latter category.

Living as we do behind two broad oceans and two friendly borders, not having fought foreigners on our soil for almost 170 years, being accustomed to winning and to regarding ourselves as No. 1, we have great difficulty coming to terms with the fact that in the nuclear age our essential homeland security has been irretrievably lost. Every other nation must cope with the reality of imperfect security; most nations do so with a shrug. For us, the idea of a threat to our Minuteman missiles, our ultimate and supposedly most invulnerable weapon, is convulsive. It epitomizes our fall from grace. We cannot, yet, stand living with the bomb.

You may find this reading a bit arbitrary. Sharpen it up. But if you concede the point that something more than the usual abstract strategic calculus is at work, you have to conclude, I think, that we have here a problem that Ronald Reagan is peculiarly suited to address. He is no phony Dr. Feelgood. He is the Real Stuff. Who could better look the nation in the eye and say, "My friends, I have sorted through the MX issue and I have an answer that is going to surprise some of you. . . .""