THE SENATE Foreign Relations Committee straddled the fence last week by voting against President Reagan's nominee to head the Arms Control and Disarmament Agency but not blocking his nomination entirely. During three confirmation hearings. Kenneth L. Adelman cast doubt upon his own integrity and demonstrated his incompetence by repeatedly wavering when asked fundamental questions about arms control. By sending debate on Adelman's fate to the Senate floor, the Committee is only prolonging a problem it should have resolved quickly and decisively. Adelman should not be the chief U.S. arms control official.

According to New York Daily News reporter Ken Auletta, Adelman reportedly said in a May 1981 interview that arms control negotiations were a "sham." Auletta provided his notes and telephone bills to prove the validity of the accusations, which Adelman denied under oath. It is difficult to believe Auletta invented an interview with Adelman, particularly since the transcripts were published in the Daily News two years ago and never questioned until this week.

Even if Adelman is telling the truth, lack of experience in the arms control field should rule him out for the job. While Adelman has served as deputy U.S. ambassador to the United Nations, he has no field experience in arms negotiations. And during the confirmation hearings, it seemed he had no opinions on the best ways to limit nuclear weapons. Asked, for example, what he thought of the "no-first use" proposal put forth most recently by George Kennan. McGeorge Bundy and Robert McNamara. Adelman replied that he hadn't "thought about it enough" to answer.

The views that Adelman did express were often so extreme that they raised questions about his potential effectiveness as a negotiator. He said that he would not seek the ratification of the underground nuclear test ban treaty and the treaty on the peaceful uses of nuclear explosions, claiming they are unverifiable. Adelman also expressed skepticism about past arms accords like SALT I.

Both stances show his ignorance of arms control pragmatism. As Senator Larry Pressler (R.-S.D.) said. "If we can't accept these treaties, we'll never get an agreement with the Russians." And for all the flaws of SALT I, it did succeed in putting a ceiling on several weapons systems, and every little bit helps.

Adelman's position on the treaties is symbolic of the Reagan Administration's "all or nothing" approach to arms control. Like the Administration. Adelman wants deep cuts in nuclear weapons and nothing less. Such a negotiating strategy--typified by an unwillingness to compromise on the zero-option proposal for Europe--is unrealistic and can only lead to stalemate. An arms control chief who is not flexible can hardly be called competent.

The necessity for some kind of tangible progress in the negotiations with the Soviets is not merely symbolic. Our allies in Western Europe, concerned about the potential effects of a growing peace movement, are depending on the United States to show some commitment to arms reductions. And the old arguments about the tragic waste of resources and the dangers of proliferation, not to mention the threat of an accidental detonation, remain true. The nomination of Adelman is a big step in the wrong direction.