THE axiom that this country's tangled Selective Service System is bound to be unfair to somebody fell with a crash on the Harvard community yesterday. The National Security Council's draft directive puts almost all college seniors and most first-year graduate students at the head of the line for next year's draft calls. No one here next year will be able to believe President Johnson's reassurance that United States society can continue to roll along in the face of the Vietnam debacle. Three-quarters of the second-year law class will go off to war, and there will be similar depletion in all other University graduate schools.

Ending deferments for graduate students could plausibly be part of the thorough reform the Selective Service System needs. But combined with the present policy of drafting the oldest men classified 1-A first, yesterday's directive is a bit of careless expediency--clearly unfair to the students who would have filled the nation's graduate schools next year. General Hershey's statement that a random age mix could not be feasibly implemented is a commentary on the disarray of Selective Service administration, which needs reorganization as badly as its system of deferments.

The National Security Council directive comes just a week after President Pusey pleaded to a congressional subcommittee for a more equitable mix. The decision is a slap in the face to Pusey and the academic community for which he spoke. It is even a disservice to the military, which General Hershey himself has said is worse off with older men than young draftees.

The inequitable action does have two pale virtues. Johnson has ended the shameful delay which threatened to leave the status of graduating seniors unresolved until next fall. And the National Security Council has avoided the folly of trying to sort out some fields of graduate study as more worthy of deferment than others.

There is a faint hope that Johnson's egregious mishandling of the draft dilemma may stir Congress to implement Senator Edward M. Kennedy's Selective Service reform bill--which would substitute random selection for the oldest-first policy. If Congress, like the President, avoids reevaluating the bizarre draft system, it will continue to exacerbate American frustration with an irrational war policy.