As the 1980 presidential election campaign reached its peak in late October, Ronald Reagan was so concerned about Jimmy Carter's charges that it was war prone that he bought a half-hour of television network time to reassume the public that he was against the Strategic Arms Limitation Treaty.

"As president," he said, "I will immediately open negotiations on a SALT III treaty. My goal is to begin arms reductions. My energies will be directed at reducing destructive nuclear weaponary in the world -- and doing it in such a way as to protect fully the critical security requirements of our nation."

Between the election and his inauguration, however, Reagan apparently had second thoughts. At a new conference, he went out of his way to reassert his longtime cold war stance. He denounced detente with Moscow as a one-way street. It was the policy of the Soviet leaders, he said, "to lie, to cheat . . . to commit any crime to achieve would domination.

That statement not only surprised many Americans, but startled and disturbed our NATO allies. Did it mean detente was irretrievably dead? Was the president turning his back on new SALT talks, as well as negotiations for a reduction of forces on the European front?

If not, what did it mean? Later comments by administration spokesmen added more confusion than clarification. Although the president is about to complete his first 100 days in office, on one at this point is certain what his ultimate policy toward the Soviet Union will be.

James A. Baker III, the White House chief of staff, said the president's statement was intended to send Moscow the message that "it is not going to be business as usual." Reagan, he added, "might have trouble trusting" the Soviets in view of their past deeds.

Secretary of State Alexander Haig has been quoted as telling Soviet Ambassador Anatoliy Dobrynin that "all new Soviet-American agreements, including arms control, trade and financial credits, will be held up" until the United States is satisfied about future Russian behavior.

More recently, through, Haig and Hans Dietrich Genscher, the West German foreign minister, reportedly agreed that negotiations with Moscow on limiting medium-range nuclear missiles based in Europe should be resumed and that consultations with allies on how to go about this should move ahead rapidly. But seven weeks have elapsed with no further public developments. So far as is known, the arms limitation question has not even been formally addressed by the National Security Council.

The president, of course, was partly out of action for several weeks while recovering from an assassination attempt, but now that he has fully resumed command he is certain to feel growing pressure from allies to clarify his intentions toward the Soviet Union.

The uneasiness of our NATO partners was aggravated by Navy Secretary John Lehman's statement against continued observance of the SALT agreements signed with Moscow in 1972 and 1979, and by the declaration of Richard Pipes, the Soviet expert on the National Security Council, that war with Russia was inevitable unless the Soviet abandoned communism.

Both statements were disavowed by other administration spokesmen (not including Reagan), but the alliance is now further disturbed by the prospect of having two avowed critics of SALT appointed as the top officials of the U.S Arms-Control and Disarmament Agency and, hence, in charge of any future negotiations on arms reductions.

One reason there is so much concern over indefinitely delaying the resumption of SALT negotiations is the fear that one of the two superpowers may elect to break the existing, but unratified, limits in a radical way, as recommended by Lehman.

The growing schism between the United States and its Europeans allies centers on conflicting reactions to recent policy declarations by Soviet President Leonid Brezhnev, who has responded to harsh U.S. rhetoric with studied restraint, almost ostentatiously turning the other cheek. In a Feb. 23 speech to the Soviet Congress, he called for a summit meeting with Reagan, and proposed a moratorium on new nuclear weapons in Europe as a step toward limiting missiles in the area.

Since then, Brezhnev has personally written Reagan and other NATO leaders, renewing his appeal for a summit session. A few days ago he called on the United States to join Russia in banning military activity in outer space. "We refuse to take part in the funeral of detente," comments Sergei Losev, the general director of Russia's official news agency.

While the West Europeans are not unskeptical, they are loath to dismiss these overtures out of hand. They see little to be lost by putting Brezhenev to the test, so that, if he is not speaking in good faith, the hollowness of his proposals can be exposed to the whole world.