IT IS TIME TO rethink American nuclear strategy. For more than 40 years, American nuclear policy focused on deterring the Soviet Union from attacking the United States and its allies. Each side built thousands of nuclear devices. Each side warned its citizens that the other side might attack without provocation at a moment's notice.

But the worst case scenario never occurred. The superpowers sublimated their nuclear tensions into conventional battles between third-world puppet governments and rebel groups.

With the development of the U.S.-led, uni-polar world, the rules of the game have changed. The remaining Soviet republics are still reeling from the autonomy they announced in August. Eastern European countries have experienced the pleasures and pains of the transition to democracy and market-based economy for the past two years.

With the decline of tensions in Europe, it is now third-world dictators and terrorist groups who are greater threats to stability than the superpowers. Future crises are more likely to resemble Iraq 1991 than Cuba 1962.

New games require new strategies, and President Bush has announced important changes in American military policy. His ideas should be judged by how well they protect American strategic interests in the emerging world order.

Cutting tactical nuclear forces and reducing alert statuses are positive steps; maintaining the B-2 bomber, as the President still wants to do, is not.

BUSH'S DECISION TO remove battlefield nuclear weapons from Western Europe makes sense. For a long time, those weapons have caused friction between the U.S. and allied countries who do not want missiles on their soil and nuclear-armed ships in their ports. The large numbers and decentralized operation of tactical nukes create the risk of accidental firings and terrorist strikes.

In the past, supporters justified these weapons in spite of the drawbacks, because of the need to deter a Soviet ground advance against Western Europe. Given that the current state of the Soviet Union makes that invasion rather unlikely, American tactical nuclear forces in Europe have outlived their mission.

The proposal to relax even long-range nuclear posture is appropriate. Reduced cost and reduced probability of accident should certainly follow from reduced superpower tension. American bombers, which Defense Secretary Dick Cheney says can be made ready within one day, do not need to be on round-the-clock alert anymore.

The missiles eliminated under the Strategic Arms Reduction Treaty, which were going to be destroyed over the next seven years, might as well be deactivated now as a sign of good faith. Multiple Impact Re-entry Vehicle missiles (MIRVs), destabilizing because of their first-strike vulnerability and likely hair-trigger use, are also excellent choices for termination.

NUCLEAR REDUCTIONS, however, should not be pushed too far, and the United States must retain some missiles despite the temptation to keep cutting. The Soviet Union will still have enough nuclear missiles to destroy the U.S. after this round of reductions, as will China

In the new game, as in the old, deterrence is an important strategy. Submarine-based missiles, for example, should continue to be retained in order to maintain the principle of mutually assured destruction with less risk than land-based MIRVs.

However, the U.S. doesn't need to develop the B-2 bomber. The bomber's primary mission is to attack targets deep inside the Soviet Union, an obsolete holdover from an earlier game. B-2 supporters say that the bomber can also be deployed in smaller conflicts, citing the effectiveness of stealth technology in the Gulf War.

But using the B-2 bomber on such missions would be like driving a Porche to the neighborhood Store 24--a Yugo could do the job just as well for much less money. It might be valuable to research stealth technology, but it would be foolish to spend $60 billion producing an unnecessary machine.

A STRONG, MOBILE, conventional military force should be an essential part of the new American form of deterrence. Removing tactical nuclear weapons from the battlefield makes local wars more likely.