The derailing of SALT II: another curve in the path to arms control?

The Russian-American cleavage is growing. But it remains to be seen if "detente" will lapse back into an unrestricted cold war. A slender strand of agreement still binds the two nuclear superpowers in their effort to control nuclear armaments -- the protocol of the strategic arms limitation treaty, known as SALT II. However, President Reagan demands concessions from Moscow before utilizing this agreement.

Looked at from Washington's point of view, the Soviets have made agreement difficult by the following steps:

* Their December 1979 invasion of Afghanistan.

* Using Cuban mercenaries to intervene militarily in various trouble spots.

* Their continued stockpiling of armaments. Many now believe the Soviets have overcome America's previous predominance and now are in a position of rough equivalency, if not superiority. The Soviet's new category of submarines is a dramatic example.

* The escalating war of words coming from Moscow.

But, looked at from Moscow's viewpoint, the United States has complicated matters:

* After negotiating an arms control treaty through the Nixon, Ford, and Carter administrations, the US Senate has not accepted the SALT II treaty.

* Carter responded to the Afghan invasion by limiting grain and technological exports and boycotting the Olympic Games.

* The new administration proposes one of the greatest arms build-ups in its history.

* President Reagan leads the apparently hardening mood of America by repeating assaults made earlier. He told reporters at his first news conference that communists seek "world revolution," for which they "reserve the right to commit any crime -- to lie, to cheat."

Failure to reach some understanding between these two opposing superpowers is too awesome for most people to consider. It is assumed that relations won't deteriorate further.

Earlier this week, Reagan told reporters he is prepared to hold arms talks with the Soviets. But he indicated these conditions: Moscow must show peaceful intentions by limiting aggressive initiatives in various areas and accept America's present determination to reenforce its own security. Furthermore, Moscow must agree to accept some actual "reduction in nuclear arms" in any future treaty.

Reagan argues that the stalled SALT II treaty is "fatally flawed" because it gives undue benefits to the Soviets and legitimizes, instead of reduces, nuclear weapons.

The situation on the SALT II treaty can be traced back to the early days of the cold war. The cold war continued through the period of America's nuclear superiority and the administrations of Presidents Truman, Eisenhower, Kennedy, and Johnson. The "Cuban missile crisis" in 1962 caused Nikita Khrushchev to back down in the face of US superiority. Growing US anxiety over communism found expression in politics and produced the near-hysteria of McCarthyism.

Richard Nixon's policy of favoring strategic superiority during the 1968 election later changed to so-called "sufficiency." He had been one of the earlier critics of alleged "softness" in the fight against communism. But Nixon visited Peking in 1971 and also visited Moscow.

The Moscow trip led the way to SALT I, which was followed in 1972 by a freeze on certain types of arms construction -- known as the ABM Treaty of 1972. At this point, the cold war had warmed up to a suspicious kind of detente.

It was assumed that SALT I -- which the Senate approved overwhelmingly -- was just the beginning and that a path had been found to reduce the burdens and danger of nuclear confrontation. The US delegation had inserted a statement in its May 9, 1972, report, declaring that if a more complete agreement on arms limitations had not been achieved "within five years" that would "constitute a basis for withdrawal from the ABM Treaty."

President Ford began negotiations for SALT II, and 18 months ago President Carter signed the new treaty that constitutionally requires two-thirds ratification in the Senate. The Senate might have passed the treaty if Carter had pushed hard at once. But he was preoccupied and, after committee hearings, it was put aside. The Afghanistan invasion meant it couldn't pass.

Reagan campaigned against the new treaty as one-sided.

A panel of pro- and antitreaty experts assembled by the Carnegie Endowment thinks that the existing unofficial agreement can last for about a year if both the US and USSR avoid actions that could frustrate the known techniques of arms control. Neither nation has any pressing reason for breaking out of the existing limits, the panel declares. But there are irreversible steps of deployment that would put pending arms co ntrol hopes out of reach.