President Carter would have us believe the big foreign policy/national security issue of the campaign is "peace or war" and he doesn't at all mind suggesting that Ronald Reagan is on the wrong side of it.

The way Ronald Reagan tells it, there are only bad guys (the communists and those who hang around with them) and good guy (America's firm friends and allies), and Jimmy Carter is so hung up on human rights that he can't see the difference.

That's been about the size of the foreign policy debate in the campaign so far -- which is to say, very small. Carter, after all, has a record of performance that includes success in tough battles: "normalization" with mainland China, the Camp David accords, the Panama Canal treaty, the lifting of the Turkish arms embargo, economic aid for the Sandinista revolutionary government in Nicaragua, U.S. sales of military aircraft to Saudi Arabia.

But when it comes to campaigning, he seems not to have the courage of the convictions that carried him into those battles. So instead of talking about what he's done, he talks mostly about the hair-raising things he'd like us to think that Ronald Reagan would do.

For his part, with such exceptions as his clumsy plunge into China policy and his pledge to scrap the SALT II treaty, Ronald Reagan talks mostly not of what he would do, but of what he would have done -- with an ultimatum here and a dark threat there -- to deter the Russians in Afghanistan, free the hostages in Iran, rescue the Pueblo and remove that Russian brigade from Cuba.

The irony is that while Carter would picture Reagan as a man who would shoot from the hip, Reagan has condemned himself to shooting, pretty much, from the lip. "We now face a situation in which our principal adversary, the Soviet Union, surpasses us in virtually every category of military strength," he has said. How he would deal with such an adversary, while he was remedying this country's military deficiences, he hasn't said. Still less has he said how he would pay for it.

It is not just thin gruel, insulting to the intelligence of the electorate. It inflicts a needless deprivation on those who would weigh foreign policy concerns most carefully in their choice of a president. Needless, that is, in the sense that there is a world of difference between the attitudes and approaches of the two men -- or two worlds, you might say -- and more than enough room for honest argument.

In Ronald Reagan's world, the communists are on the march, implacably, and "vacillation," "appeasement" and "aimlessness" have been the hallmarks of U.S. foreign policy. (Remove those words from the Reagan campaign vocabulary, and he would be almost speechless.) Concern for human rights is an indulgence, when it gets in the way of support for an anti-communist government.

There is no room in this world for countries newly emerged from colonialist rule, with a natural antipathy for their former. Western rulers. There is no recognition of native, nationalist impulses or of the whys and wherefores of working both sides of the superpower street. Still less is there tolerance for those working primarily the Soviet side of the street, while professing to be "non-aligned."

It is, roughly, the world of John Foster Dulles, in which nonalignment was immoral and the "necessary art" was to push confrontation with the Soviet Union, across the board, and right up "to the brink" -- a world when American nuclear superiority was unquestioned.

Jimmy Carter's world is one of rough military equivalence between East and West, arrived at not simply by matching the U.S.-Soviet numbers, but by balancing forces of all sorts on each side. That means including the North Atlantic Treaty Organization and the Warsaw Pact, for example, and making allowance for their respective reliability. It means counting China as anti-Soviet.

It is a world of almost infinite variety in the depth and durability of allegiances. "Anti-American" doesn't automatically translate into "pro-communist." Nationalistic versions of Marxism aren't necessarily all bad. Neither is non-alignment, even when it doesn't take the form of the purest independence from influence and support from either side.

This world most closely resembles that of John F. Kennedy. Not the one whose inaugural exhortatory address promised that "we shall pay any price, bear any burden, meet any hardship, support any friend, oppose any foe to assure the survival and the success of liberty." I'm thinking of the later Kennedy, in the last year of his presidency, who spoke in a more measured way of helping make the world "safe for diversity."

This is not to say that Carter has made the best of the world as he sees it -- far from it. It is to say that he and Reagan see fundamentally different worlds, that the differences can be identified in his performance and in Regan's pronouncments, but that the candidates themselves aren't helping much. This is the first of several columns that will attempt to give some definition and precision to their differences.