President Reagan convened a meeting of the National security Council on the situation in Lebanon yesterday amid deepening concern that Israeli military action would endanger U.S. interests throughout the Middle East.

There was no report of an Israeli military decision to bomb the Syrian antiaircraft missiles in Lebanon, and administration officials expressed belief that such action is not likely for several days at the earliest.

Neverthless, the continuing inability of special U.S. envoy

Neverthless, the continuing inability of special U.S. envoy Philip C. Habib to make headway toward a diplomatic solution was viewed as ominous, because without some sign of progress, Habib's mission may soon lose its credibility.

The veteran U.S. diplomat, in Jerusalem yesterday, was reported to be preparing to fly to Riyadh to see King Khalid, Crown Prince Fahd and other top officials of Saudi Arabia, which is a behind-the-scenes actor in the Lebanon drama and a crucial country to U.S. interest in the area.

The Saudis, according to diplomatic sources, are urging the United States to sponsor a compromise based on assurances from Washington that Israel will not attack Syrian military forces on Arab peacekeeping duty in Lebanon. Syrian President Hafez Assad, in the Saudi view, would remove the surface-to-air missiles from Lebanon if such assurances were given.

Such a plan would distinguish between Israeli reconnaissance over-flights of Syrian forces in Lebanon, which could continue, and Israeli military action against those forces.Israeli engaged one another in the Lebanese arena.

The shooting down of two Syrian helicopters over Lebanon April 28 by Israeli jets, part of a chain of escalatory events, led to the Syrian deployment of surface-to-air missiles.

The Saudis are reported to have played a role in convincing Assad, who earlier had refused to receive a U.S. emissary, to meet Habib during the diplomat's mediation shuttle.

While Riyadh's oil wealth countinues to subsidize Syria, Saudi leaders do not believe their influence alone can convince Assad to take any action, such as withdrawal of the missiles without a face-saving justification, that could endanger his position with the Syrian armed forces.

There is little doubt, according to both U.S. and Middle East sources, that Saudi Arabia and other oil sheikdoms of the Persian Gulf as well as other Arab states such as Jordan and Iraq would back Syria in the event of Israeli military action.

The Syrian forces are in Lebanon under the aegis of the Arab League, which would be immediately involved.

How strong that support would be, and to what degree it could turn into an anti-American drive, would depend on the nature and duration of an Israeli-Syrian clash and on the U.S. position.

Washington analysts have expressed the view that the Arab reaction to an Israeli strike limited to the Syrian missile sites could be short-lived. The danger is plain, though, that a strike might not be so limited, either because Israeli objectives were more ambitious or because Syria took a next step to counter the Israelis.

The Soviet Union has made clear, according to U.S. sources, that it will provide Syria with replacements for any of the Soviet-made surface-to-air missiles destroyed by Israeli attack.

If the Russians continue the missile supply and the Syrians continue missile deployment in Lebanon, the Israelis will face a decision on still stronger action, perhaps involving Syrian territory.

Senior U.S. officials are increasingly concerned about the possibility that a military clash would bring about polarization in the region that would jeopardize American interests and standing.

The impact would be substantial both on the Reagan administration's high-priority effort to improve American security arrangements in the Middle East, and on the U.S. role in the Middle East peace process.

Beyond this, the superpower stakes are also high.

Syria represents the most politically important Soviet toehold in an area where the influence and role of the Russians have been dimished in recent years. In the event of a new clash, American officials fear, the Soviet role could grow anew.