The rhetoric is cooler, but Mideast pot boils on

For the moment at least, the lid is staying on the Lebanese pot. Tension has been in noticeable decline since early this week, with both Israel's Prime Minister Menachem Begin and Syria's President Hafez Assad refusing to give ground but toning down the provocative rhetoric.

Mr. Begin's offer to hold peace talks with Lebanese President Elias Sarkis was dismissed May 26 as unrealistic. And Beirut residents, contacted by phone, reported the city abnormally quiet and said streets were busy with everyday commerce.

But the crisis is far from over, and the pot could reheat any time. So far the situation has been calmed through the combined time-buying efforts of US envoy Philip C. Habib, behind-the-scenes Saudi Arabian diplomacy, and inter-Arab measures designed to give Mr. Assad the confidence and moral support necessary for him to eventually moderate his stand. Statements of support by Arab foreign ministers meeting in Tunis last week and by heads of Gulf states meeting in Abu Dhabi this week fall into this category.

Both Mr. Assad and Mr. Begin have been severely criticized by Arab, Israeli, and Western diplomats and commentators (speaking in private) for pursuing blind brinkmanship and for using Lebanon as a pawn in a Mideast power struggle.

Both leaders have, in fact, realized short-term gains: Assad finding pan-Arab support for his confrontationist position, Begin erasing a 3-to-1 deficit in public opinion polls vis-a-vis the Labor party and running even, or ah ead, going into the June 30 Israeli elections.