THE HOUSE is about to vote on a measure requiring 18-year-old men to start registering, after the 1980 elections, for the draft. The vote is being taken under conditions that make success unlikely, and that is just as well. For the issues involved are momentous and complex, and neither the country nor the Congress has yet been attentive enough to them to ensure that a good overall decision will be made. As educational vehicles, the House measure and a similar Senate bill, due to be debated later, are useful. But it would be unfortunate to make a national commitment strictly on the basis of these debates.

Peacetime registration, after all, is a step back toward a draft, and a draft is a good deal more than a procedure for furnishing military manpower. It involves technical judgments on what sorts of forces the nation requires, and this in turn requires political judgments on the sorts of defense and foreign policies those forces are meant to serve. Moreover, the draft - involuntary military service - involves social judgments on the kind of society Americans wish to build. No bill on registering 18-year-olds can avoid reaching these larger questions, and the current House and Senate measures have served to raise them. But they have not yet been adequately weighed.

This is not to say that the all-volunteer force instituted after draft calls were suspended in 1973 (the registration requirement was was suspended in 1975) is the signal success its more ardent defenders claim. Nor is it to ignore the substantial problems of the active reserve and, especially, the individual ready reserve, which provides replacements for casualties in a European war - the contingency most on the minds of manpower planners. Ending the draft unquestionably contributed to reserve problems by removing the draft's spur to reserve service. Responsible discussion has been obstructed, moreover, by the Pentagon's refusal to declassify the results of its mobilization exercises, which apparently revealed certain reserve deficiencies. The numbers cannot be unfamiliar to the Russians. They should be made available for American public examination.

The Carter administration came to office politically disposed to associate the draft with the unpopularity of Vietnam, and therefore little included to think about reinstituting it. Its officials now argue that, notwithstanding the travails of the all-volunteer force and the diminishing pool of 18-year-olds, manpower needs can be met into the 1980s by means other than the draft: better recruitment, incentives for retention of experienced servicemen, etc. Many citizens opposed to registration, however, prefer to pick up on themes popularized during the Vietnam war. They see registration as the camel's nose under the tent of (beyond the draft) an adventurist foreign policy and a militarization of American society. Still others feel the draft should be treated as a social project and linked to some concept of universal national service for youth. The administration, striving to make the all-volunteer force work better, has hoped to preempt the wider, hotter debate.

If the all-volunteer force were problem-free, however, the draft issue would not have been revived in the first place. Fortunately, the problems are of a scale that permit, indeed demand, orderly scrutiny. That scrutiny should not be crowded by a hasty proregistration decision in the House.