Keeping watch on weapons

A succession of problems involving costly US weapons systems warrants the close attention of Congress and the American public. Consider:

* In late July the first operational test of the Pershing II rocket turned into a dud for the Pentagon when the missile roared into the sky and promptly flipped over and had to be exploded.

* The General Accounting Office reports that Air Force and Navy cruise missiles have failed operating tests. In the case of the Navy, two of four cruise missiles launched between July and mid-August missed their targets.

* The M1 tank has had repeated breakdowns and prompted concerns about its viability as a battlefield weapon in light of advances in antitank weaponry.

* A House committee staff report calls the Navy's newest cruiser, the Ticonderoga, overweight and in danger of capsizing. The Navy, however, disputes the report about the ship, which is the first to be built in a class of vessels that could eventually total between 18 and 24.

What's going on? Are these incidents coincidental, or is there something wrong with the current state of American technology or with the Pentagon's weapons policy?

Given the fact that the Reagan administration is committing billions of additional taxpayer dollars to defense in the next few years - even while cutting back funding for social programs - the answers need to be thoroughly searched out.

Modern weapons, of course, are highly complicated systems, often involving numerous components. The Pentagon is fond of arguing that such weapons are far more efficient than their leaner counterparts of years back - citing, for example, the sophisticated and expensive Sparrow missile, the mainstay of the expensive F-15 Eagle jet figher. Yet, as an article by defense specialist William Lind in the September Harper's illustrates, there is evidence that in both the short Falklands war and the more intense Lebanese conflict of recent weeks, the missile that in fact worked best was not the Sparrow but the far less costly and less complicated Sidewinder missile.

Added to the problem of oversophistication is the current defense practice known as ''weapons concurrency.'' Weapons concurrency means the process of testing weapons and producing them at the same time. It is a traditional but fairly costly practice and was in vogue during the Eisenhower years of the 1950s as well as during much of the Vietnam period. The Pentagon changed that system somewhat in the 1970s, when Melvin Laird and businessman David Packard were in the top defense slots. They shifted the emphasis to ''fly before buy'' - a logical practice followed by most commercial business firms.

During the Carter years, the policy again gradually shifted back to concurrency, and it has been greatly expanded under the Reagan administration, which is eager to launch a broad range of new weapons systems as quickly as possible as a counterweight to the Soviet military buildup.

Are the American public and US national security best served by such a policy? The Pentagon itself has indirectly acknowledged that it is deeply concerned about the $15 billion cruise missile program. It recently ousted the head of that program.

Some steps toward accountability in the procurement process have already been taken. Congress has written into law a requirement that the Pentagon must explain any weapons cost increases above 15 percent. Lawmakers have also established a new civilian inspector general's post to help detect waste and fraud within the Pentagon. And defense officials themselves are implementing a program of some 32 new initiatives to make weapons procurement more efficient, a program begun last year by Deputy Defense Secretary Frank Carlucci.

But closer oversight is needed. It is strange, for example, that despite the huge increases in defense spending there is no congressional committee (comparable to the Truman Committee of the early 1940s) ferreting out waste in the defense establishment.

Also, lawmakers should be looking at the notion of concurrency itself. That is not to deny the need for new weapons in the American arsenal. But if US defense planners are to go ahead with production of such costly systems as those now planned, they would seem to be warranted in doing so only upon solid proof that the systems actually do the job they are supposed to do.