Should US and USSR fear each other?

Russians and Americans try to understand each other. It is a strange relationship. Each fears the other; each wonders about the other. And I suppose (without being morbid about it) that each could destroy the other. There have been various stages in this confrontation; under Nixon, Ford, and Carter things for a while seemed to be getting better and the SALT I treaty was signed; then came the reverse with Afghanistan, Poland, and the rejection of SALT II.

Roly-poly Soviet premier Khrushchev came to America in 1959 and he did not seem very terrifying on our special train that toured the West. I remember one morning on the hill in San Francisco how impressed he was with a municipal pick-up truck that took the trash, compressed it, and ingurgitated it before you could wink. Everybody was careful not to say to him directly, ''They don't have things like that in the Soviet Union.''

But that was the thought that Khrushchev expressed at the 21st Soviet Communist Party gathering in Moscow that year where he made the seven-hour keynote address. He said Russia was going to bury the United States. The new seven-year plan he said, would expand Soviet production 8.6 percent annually compared to the paltry 2 percent annual expansion in America, and it would give Russia the ''decisive edge'' by 1970. I knew economists here who worried about it. He warned, too, about US planes flying around the USSR with atomic bombs. ''Someone may lose his head; anything can happen,'' he said. That was 23 years ago.

How preposterous those Russian boasts were. Newsweek has just published (April 12) an article, ''A System That Doesn't Work,'' about the Soviet economy. The Russians can't feed themselves, they import grain from us, the factories are inefficient, and their immense war machine puts a terrible burden on the people. In the slow-motion economy and repressive system a quarter of the Soviet work force remains on the farm compared with less than 4 percent in the US.

Should Americans sneer or tremble at Russia? Perhaps both. President Reagan at his June 29th press conference last year said the Russians would ''commit any crime . . . to lie, to cheat . . .'' And on his trip last week to Barbados he said that Grenada had joined the Soviets to ''spread the virus'' of Marxism in the region.

Now and then comes a voice that asks if we are carrying this thing too far. In his Dartmouth speech last November George F. Kennan, former ambassador to Moscow, said that the tendency to view all aspects of the relationship in terms of a ''supposed total and irreconcilable conflict'' is unrealistic; such sentiments, he argues, ''are not the marks of the maturity and realism one expects of the diplomacy of a great power; they are the marks of an intellectual primitivism and naivete unpardonable in a great government . . .''

There is certainly danger in a situation where fearful antagonists confront each other with nuclear weapons. Professor John E. Mack in the current issue of Harvard magazine asks if the two nations are not in the grip of what he calls ''the devil theory.'' He quotes law professor Roger Fisher to the effect that the more nations disagree the more urgent it is that ''we maintain lines of communication and talk about our differences.''

Now a great groundswell of antinuclear feeling is pressing on Washington and a dozen new books describe the risk of war. I have rarely seen anything like it. In the past at times of war hysteria it was directed at some concrete enemy; now the apprehension is generalized. It is a kind of antiwar hysteria. The argument runs that conventional war leads to nuclear war; that nuclear war can in no way be limited; and that there are no victors. It is a predicament for war-prone mankind.

George Kennan calls our fear of Russia a ''morbid preoccupation.'' Perhaps this is as much a religious matter as it is a temporal matter. He urges us to ''turn our attention to the real challenges and possibilities that loom beyond it, and in this way restore to ourselves a sense of confidence and belief in what we have inherited and in what we can be.''