Like the Gilbert and Sullivan policeman, the life of a secretary of defense is rarely a happy one. Caspar Weinberger is verifying this fact as he tries to find a mode for deploying the MX missile capable of satisfying the numerous critics, political, military and industrial. At the same time, he faces the strong possiblilty of sharp reductions in the funds to be available for his military programs.

Weinberger is already being criticized for having invited cuts by delaying decisions not only regarding the MX but also the new bomber, the big carrier issue and other pressing matters. Nevertheless, a strong case can be made for further deliberate delay. Now would be an excellent time to take a recess and review the essentiality of all high- priced military programs. By doing so, when the cuts come, our leaders would have solid evidence of the programs' relative importance and rational priority in distributing budget reductions.

If the secretary undertook such a review, he would need a practical measure of essentiality to apply to the projects to be tested. I have one such measure to propose in the form of a definition: an essential military program is one that produces effective military means to cope with a real and urgent danger at a price deemed acceptable. Price may be expressed in many ways; money, manpower, industrial output, scarce natural resources and the effect of reductions on other programs. In short, for essentiality the danger must be great, the planned counter-measures seemingly efficacious and the price right.

If such a measure were strictly applied to some of the major defense programs, I would expect many to flunk the test. Let me illustrate how several tests might turn out.

In the case of the MX, the urgency of the threat can be challenged because of the extremely low probability that the cautious leaders of the Kremlin would ever risk an attack on our silo-based ICBMs, given the uncertain performance of their own missiles and the losses to be expected from an American retaliation. In the absence of an urgent danger, there is an unproved requirement for an MX or any other weapon basing its need on the vulnerability of our ICBMs.

The administration is proposing a new bomber in replacement of the B52, capable of penetrating heavy Soviet air defenses. For test purposes, it would be necessary to show that such a bomber could penetrate more effectively and/or at lesser cost than cruise missiles launched from aircraft, submarines or surface craft. Until this point is cleared, the bomber program cannot be certified essential.

The Navy wants three new Nimitz-type super carriers, each of which, with its 100- odd aircraft aboard and its protective escort craft, will cost over $6 billion. This is high- priced air support, but there have been situations in the past when carrier aircraft have been most welcome. The question facing the administration is not whether we will henceforth need aircraft carriers but whether our needs will be better served by more numerous small carriers deriving their firepower primarily from missiles rather than a few big ones depending for firepower on expensive, sophisticated aircraft.

Before deciding this matter, I would recommend that the authorities rehear the case for small carriers made by such authorities as retired four-star Admirals Zumwalt, Bagley and Turner. Personally, I would cast my vote for their side of the argument. The means they recommend appear more effective and the price more favorable than the alternative.

In the case of the Army, I would question the essentiality of the two additional divisions under consideration to raise the Army total from 14 to 16. While there may be a definite need for more Army divisions later on, no such expansion can be justified now until each of the 14 divisions is made task- ready--that is, prepared to undertake its primary mission on schedule and stay with it as long as required. It would make much more sense for the Defense Department to expend its resources for task-readiness than to add to the divisional structure and thereby the "hollowness" that the Army Chief of Staff, Gen. E. C. Meyer, deplores in the Army at pre sent.

Looking over the expansion plans for the Marines, one might question the essentiality of the $9 billion item for acquiring over 300 Harrier short take-off fighter aircraft to improve the quality of their air support. These aircraft plus a considerable increase in their tank elements would better allow the Marines to take over ground-fighting missions beyond their aging speciality of amphibious operations. But inquiry into the Harriers might suggest a related question--why do the three Marine divisions have their own air force, whereas the 14 Army divisions must look to the Air Force for support? This, in turn, would open the Pandora's box of service roles and missions with their costly duplications--something no administration in its right mind would wish to do in times like these.

If Secretary Weinberger were inclined to undertake such an essentiality review, he might hope for certain gains. Such a review would verify the soundness or reveal the vulnerabilities of programs in time to correct or jettison them. This would strengthen the defense of the surviving programs against the assault of critics bent on reducing military budgets. Perhaps of longer-term importance, it might establish a permanent practice of demanding evidence of the essentiality of all future military programs as demonstrated by their contribution to forestalling real and urgent dangers rather than to the illusory need of equaling or surpassing what the Soviets have or do.