The diplomatic consequences of the Senate vote on the AWACS deal are likely to unfold gradually, not abruptly, regardless of which way the vote goes. Even if President Reagan wins, and the sale is approved, his victory may well prove a Pyrrhic one, so bruised and buffeted have the Saudis been by the domestic political wrangle in the United States over the whole issue.
As the dust settles, the AWACS row could have these meanings:
* For the US, a setback (or worse if the Senate turns the deal down) in the Reagan administration's effort to develop a strategic blueprint for defense of the Gulf based on bilateral and equal agreements with Saudi Arabia, Egypt, and Israel.
* For Saudi Arabia, if rebuffed, bitter confirmation that the combination of the Senate's foreign policy role and American ethnic politics virtually precludes Saudi Arabia's being accepted as a full partner by Washington on terms compatible with Saudi self-esteem.
* For Israel and the pro-Israel lobby in the US, if successful in helping sink the deal, victory in a relentless and hard-nosed campaign to thwart the development of any US-Saudi relationship perceived by Israelis as at Israel's expense.
* For radical or hard-line Arab governments, especially if the Saudis lose, an opportunity to repeat to the Saudi royal family the familiar argument that anybody in the Arab world counting on the US as a reliable ally is fooling himself.
* For nonestablishment Muslim militants - a growing force to be reckoned with in the Middle East - proof of their contention that the US-Israel combination is a tandem expressly aimed at corrupting, humiliating, and weakening Islam.
* For the Soviet Union, whatever the AWACS outcome, an opportunity to explore whether the new situation gives Moscow a chance to get back into the Middle East peacemaking process, from which the Russians have been excluded since the late President Sadat's dramatic visit to Jerusalem in 1977.
* For the West Europeans, an opportunity if the US deal fails, to develop a bigger and more active role as both arms salesmen to Saudi Arabia and as middlemen or negotiators in the Arab-Israel peace process.
Israelis and others who are cavalier or hectoring toward the Saudis often justify their attitude by saying that in the last resort the Saudi royal family has nowhere else to turn but to the US - regardless of any humiliation involved. But that situation makes it essential for the Saudis to be seen to respond to humiliation at US hands by countermeasures of their own.
If the Saudis are frustrated by Congress, they still have several options open:
1. Making a token cutback in daily oil production.
2. Turning to Britain to buy Nimrod surveillance aircraft instead of the US AWACS.
3. Establishing diplomatic relations with the USSR and perhaps encouraging other conservative Arab oil-producing states of the Gulf to do likewise.
4. Being less willing to use Saudi influence to restrain the Palestinians when the intransigence of the latter is threatening the peace of the Middle East.
5. Pushing Saudi Crown Prince Fahd's eight-point peace plan for the Mideast as an alternative to Camp David. It has been largely overlooked in the US that Crown Prince Fahd's plan has already been endorsed by French President Mitterrand as a starting point for a broader negotiation than that offered by Camp David. British Foreign Secretary Lord Carrington will shortly be visiting Saudi Arabia on behalf of the European Community and is expected to explore further the Saudi plan