Relax. Even though you spent the last weeks reading "At The Crater's Edge" in the morning and "The Fate of The Earth" in the evening, it won't happen. Let your friends and neighbors spend their Sundays digging bunkers in the Shenandoah. Let the worry warts in the city attend the Ground Zero meetings. You stay home and empty a six-pack with a night of Super TV.

And at your next PTA meeting, when anxious parents pass out routes to your host city, be prepared to squelch the nervous nellies with selected theories as to why not even one of those more than 100,000 nuclear warheads will ever be fire. In addition to the standard argument that it would be suicidal to start a nuclear war, try these:

1. The Yellow Peril Theory. If there's anything the Russians fear more than America, it's the Chinese hordes. Nuclear war between the United States and the Soviet Union could leave the Chinese with nothing to do but man the scoreboards.

After the dust (radioactive, to be sure) settled, the Chinese would march on Moscow with nothing more in their way but an occasional pile of bricks. China and Japan would become the premier powers not just of the Pacific, but of the entire globe.

Many people believe that even the slightest prospect of Chinese world dominance so dismays the Soviets that a nuclear war with America is impossible. Further, a two-sided nuclear war with both China and America mounted by the Soviets is certain to result in a loss for the Soviets.

2. The Bread Basket Theory. The Soviets have had crop failure after crop failure for nearly a decade. On the other hand, America ships wheat and other agricultural products to nearly every country in the world. Many international experts consider food production America's best strength.

Wheat fields covered with fallout in Nebraska and Kansas would cause famine not just in Russia but in many countries unaffected directly by a nuclear war. With at least some damage done to Soviet agriculture by America, the weakened Soviets would lose tens of millions to famine in the years beyond, perhaps more than in the warfare itself.

The Soviets are well aware of their weakness in agricultural production, and of our strength. A first strike on the missile bases of Nebraska and the Dakotas would be devastating to the Russian diet even if our military response were minimal.

3. The Satellite Loss Theory. In a direct nuclear conflict between Russia and the America, nuclear weapons are targeted toward the Soviet Union. In a short nuclear war, Russia would be weakened whether it won or not.

After the conflict, the theorists believe, the Soviets would lose all control over their European satellites, from Poland to Bulgaria. In fact, some believe that the tail could wag the dog, with the Soviet Union becoming the servant nation for an alliance of European communist countries.

4. The Hard Currency Theory. A nuclear war between the Soviets and the United States would destroy this nation's banking system,and the communist governments of Eastern Europe and Russia would no longer have a friend at Chase Manhattan. That's because there would be no Chase Manhattan.

A surviving Soviet Union would have very little credit on the world stage, and commodities would be hard to come by. Although Russia mines a significant amount of gold, its value would be decreased if it were radioactive.

You see, there are many more deterrents to nuclear war for the Soviets, besides counting missiles. So the next time someone warns you that nuclear war is imminent because the other side has military superiority, tell them about the worthless radioactive corn in Iowa. The Russians are considering all this. So should Jonathan Schell.