DEFENSE Secretary Dick Cheney was right to cut his losses on the A-12, the Navy's medium-range carrier-based Stealth bomber. The difficult decision to halt the $52 billion project while it was still in the development stage should not be taken for what it was not. It was not a step toward restoring an imagined peace dividend. In the long run it is not likely to save that much money.

The secretary made clear that the Navy will continue to need a replacement for the present generation of A-6 bombers, many of which are 20 years old and showing it; among the problems are cracks in their wings. The successor is likely also to incorporate costly radar-deceiving stealth technology; no doubt as a good investment it should. But particularly as the primary Soviet threat continues to fade, the military need is less urgent, and in the shorter run the decision does provide fiscal relief.

At the same time it sends good messages in several directions. The contractors and the plane's champions inside the Defense Department had earlier misled if not quite lied to the secretary about its status, which he in turn had misrepresented to Congress. In fact the plane was late, overweight and over budget, nor was it clear its problems could be fixed. As Mr. Cheney noted in announcing his decision, "This program cannot be sustained unless I ask Congress for more money and bail the contractors out," yet "no one can tell me exactly how much more it will cost to keep this program going."

In the present fiscal climate he could not ask Congress for the money, nor did he want to give the wink to the defense industry that a bailout would imply. If an administration would say yes to this, it was hard to think what it would not say yes to.

So Mr. Cheney did the right thing. But the fundamental problems, of course, remain. The services still have too many weapons geared to an older threat and chasing too few dollars. The threat has to be redefined, and the services and their wish lists have to be thinned to match. The department also needs to rethink its relationship in a leaner time to the industry that supplies it. These were fixed-price contracts for leading-edge development, almost a contradiction in terms. The Pentagon wanted to control costs and liked looking frugal; the contractors knew what they were signing (and perhaps expected they would later be met with precisely the traditional tolerance that Mr. Cheney has rightly refused to extend). But defense contractors are never fully private entrepreneurs.

Who does and should cover the risk in developing new military technologies, and how far should the government go, as a matter of national security, to make sure there will always be a strong defense industrial base? Mr. Cheney has once again shown himself on the A-12 to be a strong secretary. But he continues to have lots of problems, and none more important than these.