MEMBERS OF THE House Foreign Affairs Committee have asked the administration to take another look at ways to stop Pakistan's covert progress toward a nuclear bomb. They suggest the possibility of trying to "more effectively treat Pakistan's underlying security concerns" - a discreet reference to using arms sales as leverage to buy out the Pakistani nuclear option. No one can deny Pakistan's security concerns - though it is highly doubtful that a nuclear capability would ameliorate any of them - but the logic behind the "buy-out" approach is thin and faulty.

There is some important background to the current U.S.-Pakistani impasse over nuclear weapons development. When President Carter took office in 1977, Pakistan had a contract with France fo the supply of a reprocessing plant - a facility that produces plutonium which can be directly used in a nuclear weapon. A new law had just been put on the books - a congressional initiative - requiring the United States to suspend all aid to any country importing parts for a reprocessing plant. Accordingly, the government cut off aid to Pakistan while applying heavy diplomatic pressure to both Pakistan while applying heavy diplomatic pressure to both Pakistan and France. One year later the aid was resumed when it was announced that France would not supply the reprocessing plant after all. The aid cut-off cannot be given credit for the success of that effort since it was the government of France that made the decision - but certainly American firmness and constancy of purpose contributed importantly.

Shortly after U.S. aid resumed it was discovered that Pakistan was secretly pursuing the other possible route to a nuclear capability by attempting to build its own enrichment plant. Several months ago, the United States again suspended its aid programs, after several unsuccessful efforts to dissuade Pakistan from that course.

That's history. Now the congressmen are arguing that sanctions aren't enough and that the United States should look at what enticements it has to offer. "It would be unwarranted" - they say - "for critics to characterize any such initiative as a stark trade of conventional arms in return for a freeze on nuclear weapons work..." It's hard to see why such an accurate characterization would be unwarranted, since a "stark trade" is exactly what it would be. The United States has repeatedly offered to sell Pakistan a variety of weapons systems, including the F5 fighter, with no response. What Pakistan wants are the most sophisticated systems, the F16, for instance, whose sale would violate U.S. conventional-arms control policy. This would be the kind of "quid" - and symbol of U.S. commitment - that Pakistan might (and this is by no means certain) consider as a trade-off for the "quo" of abaondoning its nuclear program.

Sanctions may not prove successful in dussuading Pakistan from building nuclear explosives. But what would be the price of the precedent established by a conventional-arms bribe not to do so if one were in fact successful? As the congressmen themselves point out, if strong sanctions had been imposed after the Indian explosion of 1974, we might not be facing this problem today.