FOR THE CONTINUANCE of the deadlock on Cyprus and the further unraveling of the American position in the eastern Mediterranean, prepare to blame Sens. Sarbanes, Clark, Biden, Stone, Humphrey, Javits, Percy and Pell. Ignoring the likely impact on the Cyprus negotiations under way, they made up the majority in the 8-to-4 vote by which the Senate Foreign Relations Committee rejected the administration's bid to advance those negotiations by lifting the three-year-old Turkish arms embargo. The administration is struggling to negate the committee's vote by somehow overturning it on the Senate floor. But it is very long shot, indeed.

Note well: In three years, the embargo utterly and demonstrably failed to loosen the Turkish grip on Cyprus. It only enflamed Turkish nationalism and led the Turks to lash back by shutting down military and intelligence bases and moving toward NATO door. One does not have to love the Turks, only to understand them, to recognize that this is so.

Given the impasse, the administration sought to remove the embargo, not tying the move directly to Turkish concessions on Cyprus but expecting concessions nonetheless. The Turks responded by coming up with fresh proposals. The proposals disappointed the Greek Cypriot majority, which seeks more territory and greater power in a reunited Cyprus government. But - and this is key - the proposals remain available as a respectable basis for negotiation.

Into this diplomatic china shop the Foreign Relations Committee bull charged on Thursday. The committee majority responded, we gather, if not to the "Greek lobby's" political weight, then to its discredited argument that the Turks will alter their policy only under frontal pressure. The committee was thus intervening in a fragile negotiation, one whose rhythm and sense it is in no position to gauge, whose success it does not have the direct and primary responsibility to bring about, and whose failure it will almost certainly try to push off on the administration. It is illusory and vain of a congressional committee to imagine that in this or any other diplomatic negotiation with foreign states it can make itself even an active daily partner of executive diplomacy, let alone the dominant, decisive force. A similar congressional effort almost destroyed the Panama negotiations. Turkey, which is far bigger and tougher, cannot be mauled in the same way.

If things get worse on the tormented island of Cyprus, keep these names in mind: Sarbanes, Clark, Biden, Stone, Humphrey, Javits, Percy and Pell.