Just 15 months ago, when this presidential election was as far off as next year's World Series, the hot political issue in America was SALT II. nUnlike some issues that cannot be pushed aside, SALT had an opportunity to die, and it did.Now Ronald Reagan and Jimmy Carter have brought it back to life.

Symbolism dominated the original debate over SALT II, and in this latest incarnation the symbolism has taken over again. Jimmy Carter decided that the strategic arms limitation treaty with the Soviet Union made a good symbol for the distinction he wants to draw this fall between himself -- "man of peace" -- and Reagan -- "hipshooter."

Reagan too has made a symbol of the SALT process, promising Sunday night to bypass SALT II, which he finds inadequate and a manifestation of the Carter administration's "weakness," and to move directly toward a SALT III, which he says would provide real arms reduction, not just controls on an ongoing arms race.

In fact there is a serious reality in this SALT process, one neither candidate has bothered to address, but one which the country will have to face up to sometime during the next presidential term. The reality is that the attempt to put some control on strategic nuclear weapons -- launched by the Johnson administration a dozen years ago -- is on the verge of coming a cropper, and neither Carter nor Reagan now has a realistic plan for avoiding this outcome.

The candidates may prefer to rely on their symbols in place of the SALT realities, but the symbols won't be able to cope with the real world of the strategic arms competition. A little history makes the point.

Reagan now calls for a fresh start in the strategic arms negotiations, a proposal that puts him squarely in the negotiating tradition of the last two elected presidents. In 1969 Richard Nixon rejected the basis for Vietnam peace that the Johnson administration had negotiated with North Vietnam, insisting on starting over again. It took Nixon four more years to negotiate an agreement.

In early 1977 the Carter administration rejected the basis for a SALT II that Henry Kissinger and Gerald Ford had negotiated, insisting on an entirely new initiative to achieve "deep cuts" in Soviet and American nuclear arsenals. This initiative collapsed, and in June 1979 Carter signed a SALT II closely akin to the Kissinger-Ford version. But by 1979 the strategic competition had become much more complicated, and an agreement that might have won relatively easy Senate approval in 1977 ran into serious opposition. The Soviet invasion of Afghanistan last December forced Carter to ask the Senate to suspend its deliberations on SALT II.

This compulsion to revise the negotiating work of your predecessor obviously appeals to new or would-be presidents, but as the record suggests, it does not produce the desired results. Only in America does statesmanship revolve on a quadrennial schedule; America's negotiating partners tend to be more constant.

Reagan criticized SALT II as "fatally flawed," and defends his position as one many other public figures have taken. But this isn't exactly so. The formidable opposition to SALT II that did devleop in 1979 was based not so much on the specific provisions of the treaty as on the Carter administration's overall strategic policy. Henry Kissinger and former president Ford, for example, both said that SALT II would be acceptable provided the administration substantially increased defense spending and took steps to toughen American diplomacy generally.

In fact, SALT II would not, if ratified, inhibit any American strategic weapons program that Reagan has publicly favored. However, it would put numerous restraints on the Soviet buildup. As Reagan points out, the treaty would allow both superpowers to continue to add new strategic weapons -- it is not an amrs reduction treaty. Yet it does impose significant controls that will disappear if it is not ratified.

But can it be ratified? Even if all the current Senate's SALT supporters win reelection next month -- a longshot at best -- the treaty is in grave trouble. The invasion of Afghanistan vastly complicated its prospects, and since then a huge if little noticed new impediment to Senate approval has been introduced.

That impediment is the revelation or accusation (which it is remains unclear) that the Soviets violated a 1975 convention on biological weapons by producing a deadly toxin in the Russian city of Sverdlovsk. Using information from an unidentified source and public reports of an outbreak of anthrax in Sverdlovsk, the Carter adminstration charged last spring that the Soviets might have violated this convention. The Soviets denied it hotly, saying the anthrax was caused by meat poisoning.

Verification -- the ability to be sure of Soviet compliance -- is a crucial issue in the SALT debate. The Carter administration itself has now said publicly that it cannot verify the biological weapons convention, and suspects a violation. This case is destined to spill over into any future SALT II debate and complicate it enormously.