Philip C. Habib, President Reagan's special envoy, has resumed his peacekeeping mission to the Middle East with hopes for a Lebanon settlement slightly higher than they were when he first set out nearly two months ago.
But, for the moment, Washington's hopes are still pinned largely on Saudi Arabia and its diplomatic efforts. State Department officials are calculating that while Mr. Habib continues to buy time, the Saudis, together with other Arabs, can make further progress toward a lowering of tensions in Lebanon.
It is still far from certain that the combined efforts of Habib and the diplomats of other nations can prevent a conflict between Israel and Syria in Lebanon. But one small step was achieved recently when Saudi and Kuwaiti ministers helped to arrange a truce and the lifting of the Syrian siege of the Phalangist-held town of Zahle.
American specialists on Lebanon say that the next move to reduce tensions is expected to involve the city of Beirut. The ultimate aim of the diplomats is to reduce the Syrian military presence in Beirut and elsewhere in return for a reduction in Israel's involvement and influence in northern Lebanon. The plan is to substitute the "peacekeeping" troops of other Arab nations, less threatening to the Israelis than the Syrians, as Syrian troops are withdrawn.
One of the keys as far as the Arabs are concerned is to secure a commitment on the part of the Christian, Israeli-supported Phalangists to reduce their ties with the Israelis in return for enhanced political power. Syria has been demanding that the Phalangists formally renounce all their links with Israel. Most experts on the subject say it is highly unlikely that the Phalangists would break completely with Israel. The Israelis have provided the Phalangists with weapons that have been vital to their struggle. But the experts do think that Phalangist leaders may be willing to reduce their ties with the Israelis.
The Phalangist have already indicated that they may be willing to move in this direction. On July 7, Pierre Gemayel, head of the Phalangist Party, was reported to have said: "We stress our readiness to give any guarantee and at the same time assure that we have no relations with Israel.'
No one in Washington is certain what that means, but it is taken as a hopeful sign.
John Ruedy, chairman of Arab Studies at Georgetown University's School of Foreign Service, describes the fundamental problem in this way: "The syrians feel threatened by Israel's presence in Lebanon. . . . Israel, on the other hand, feels threatened by the Syrian support for the Palestinian commandos. . . . The way to defuse the situation is to minimize relations between the Syrians and Palestinian commandos, on the one hand, and between Israel and the Phalangists on the other. Indications are that the Phalangists are willing to play ball."
American officials, meanwhile, see Saudi Arabia, the main supplier of imported US oil, as a "moderating" force in Lebanon and in other situations. They are preparing a major, White House-supported push to win agreement in the US Congress for the controversial sale of radar plans to Saudi Arabia.
There has been speculation in Washington for several days now that the administration was about to give informal notice to the Congress of the radar plane sale, but this could not be confirmed. After formal notification is made, both houses of the Congress have 30 working days in which to disapprove the sale by majority votes. Israel and its friends on Capitol Hill are lobbying strongly against the sale.