The interesting question about the nomination of Kenneth Adelman as director of the Arms Control and Disarmament Agency is not whether it should be confirmed by the Senate. Even his spacey performance before the Senate Foreign Relations Committee the first time around was not valid justification for denying the president the arms controller of his choice.

Still less are the predispositions revealed in his past pronouncements. They are, for the most part, Ronald Reagan's predispositions--anti-SALT II, pro-arms buildup as a prelude to parleying and all the rest.

The critical issue in this case has to do with management and style. Leave aside the rightness of the administration's purposes; you would have hoped by now that it would have acquired some firmer grasp on what students of government call "process"--on what it takes to make things work.

I am thinking of form as well as substance--of good housekeeping, but also of the critical importance in politics and diplomacy of impressions conveyed and signals sent.

An ACDA director has to preside over various arms-control negotiations which run simultaneously and deal with a bewildering assortment of high-technology weaponry--negotiations now in the hands of experienced and knowledgeable American representatives. He has to deal forcefully with the Pentagon brain-trust. Finally, he will be advising a secretary of state whose particular weakness is the absence of firsthand familiarity with military matters.

On its face, then, the opening created by the enforced departure of Eugene Rostow cried out for a recognized authority on the subject. Though his second appearance before the committee was a marked improvement over the first (where he seemed to be suffering as much from stage fright as from poor briefing), Adelman obviously has a lot to learn.

But if Adelman is as smart as his supporters say he is, that part is remediable. What may be less easy to remedy is the lingering impact of that first appearance. At home and abroad, among critics of the Reagan arms-control policy, the first impression of ignorance and/or indifference will die hard.

What is not remediable is the opening missed--the opportunity to advance significantly the professed interests of the president to build confidence in Congress, in Europe and around the world in the sincerity and flexibility of his approach to arms control.

Imagine yourself in the White House, contemplating the various elements involved in a decision on a successor to Gene Rostow, who is putting it about that he was relieved of his duties for "an excess of zeal." True or not, the public impression is of shambles in the arms-control apparatus. Your critics are seizing on it as proof positive that the president's heart isn't in controlling the arms race.

You note that most of the prospective Democratic candidates for president have arms control near or at the top of their list of foreign policy issues. At home the "nuclear freeze" movement is mushrooming, fed by a budgetary crisis that is bringing ever-louder cries for defense-spending cuts. The vice president just returned from a seven-nation tour with the specific mission of presenting Ronald Reagan as a reasonable fellow, firm but flexible, and in no sense the unyielding hard-liner that Europe's anti- nuclear peace movement seems to have in mind.

It is signal-sending time--by your own admission in sending Bush to Europe, and in the extra effort of the State of the Union message to convey sweet reason and a yearning for bipartisanship in foreign policy. So what do you do? If you are in the Reagan White House, you take this golden opportunity of an opening in the top job in ACDA to project precisely the opposite impression than the one that you are trying, in every other respect, to project.

This is not to suggest that just about any candidate reasonably in tune with the administration's policy would not have encountered rigorous Senate examination and some opposition; arms control has emerged as the most incendiary issue of foreign policy. But a heavier-weight, or a better-prepared Ken Adelman, probably would not have inflamed passions, or incited political opportunism. A posse of briefers and arm-twisters would not have had to be organized in an emergency effort to rescue the nomination.

In committee and on the floor, the vote, expected tomorrow, will be a lot closer to party-line partisanship, which can only serve to aggravate the very concerns about Ronald Reagan that he is supposedly trying to lay to rest. The irony is that the choice of Adelman is probably much less a reflection of the administration's dedication to arms control than it is a definition of ineptitude.