WHETHER TO SELL AWACS radar planes to Saudi Arabia is a close question. Sensible people, including those in Congress, will approach it with deeply divided feelings. But it is a sound principle that in close questions of this particular kind Congress owes the president the benefit of the doubt. The congressional veto is properly reserved for those instances in which the administration is clearly and flatly wrong. The AWACS sale is a bad choice to have to make, and one that a more foresighted statecraft might have averted. But it can't be retrieved now, and the Reagan administration is firmly committed to it. Despite its misgivings, the right course for Congress is to let this sale proceed.

The burden of the decision is lightened a little by the knowledge that the AWACS planes are not going to be quite so useful to the Saudis as perhaps the Saudis think (and, of course, as the U.S. Air Force has been telling them). Nor are the planes going to be quite so grave a threat to the Israelis as the Israelis claim. The original American mistake was to allow those planes to become the symbol of this country's support, approval, warm friendship and so forth. The United States has every good reason to show evidence of its support, approval, warm friendship and so forth for the Saudis. Selling them AWACS aircraft is a wretched way to demonstrate that support, etc., but at the present late stage of the affair that is unfortunately irrelevant. The Carter administration favored it. The Reagan administration confirmed the offer forcefully, and to withdraw it would inflict great damage both on the American position in the Persian Gulf region and on the Saudi regime.

The Israeli view is that the Saudi regime remains an enemy, the United States is proposing to arm that enemy, and that's all anybody needs to know. But Israeli military superiority in the air--with or without a Saudi AWACS--is hardly open to question. The passionate Israeli opposition to this sale is fed by the anxiety that it means--symbolically, again--a weakening of the American commitment to Israel. That is incorrect. President Reagan's decision last week to resume delivery of the F16 fighters to Israel entitles him at least to be believed when he speaks of a concern for Israel.

Prime Minister Begin's government needs to come to terms with the message that its friends in this country have been trying for some time to deliver-- the message that the frozen rigidity of their policy toward their neighbors, and their apparently increasing reliance on air strikes well beyond their boundaries, affect the security of both the United States and Israel. When the United States works to extend its in fluence and strengthen its friends in the Arab world, surely that benefits Israeli interests as well.

The administration has left some confusion over the question of restrictions on the use of the AWACS planes by the Saudis. Congress will certainly want that question answered before it votes.

For Americans, the AWACS affair means that American statecraft has still not found a way to carry on an effective diplomacy in the Middle East without entangling itself in questionable sales of increasingly sophisticated warplanes. If Congress allows this sale to proceed, it might usefully take the occasion to urge the administration toward a political style in the Middle East that does not make the marketing of weapons the sole and supreme indicator of American good will.