Middle East roundup; Begin and Assad: Can they back down?

Israel and Syria are engaged in a dangerour game of military chicken which could bring on a war that neither side really wants. Both seem willing to fight a limited war over Syrian antiaircraft missiles moved into central Lebanon last week -- Israel to get rid of them and Syria to keep them there.

But observers here question whether any military conflict between Syria, the Soviet Union's closest friend in the Middle East, and Israel, allied to the United States, could be checked before exploding into a wider war.

Aware of this danger, both superpowers are attempting to defuse the crisis by diplomacy. Much will depend on how well each can --

Special US envoy Philip Habib is embarked on a mission to Syria, Lebanon, and Israel, while Soviet First Deputy Foreign Minister Georgi Korniyenko is on a three-day visit to Syria. But even as the diplomats speak softly, Syria and Israel are escalating their rhetoric and gestures to a point where backing down will be difficult without losing face.

Israeli Prime Minister Menachem Begin told ministers "only a miracle will get the missiles out by diplomatic means." He added that Israel "will not wait indefinitely" for their removal. The official Syrian newspaper Tishreen rejected May 7 any possibility of the missiles being withdrawn. As if to underline their point, Syria was reported by United Press International to have moved 7,000 new troops into the Bekaa Valley in Lebanon, site of the missile emplacements, and eyewitnesses claimed to have seen an additional SAM missile battery in the mountains east of Beirut. Meanwhile, Israeli planes boldly swept over the Bekaa Valley, while Israel denied an Associated Press report that it had moved in six batteries of heavy artillery into the Christian enclave of south Lebanon.

The current step-by-step escalation does not seem to have been clearly planned y either side. For many months Israeli planes bombed Syria's Palestine Liberation Organization (PLO) allies in south Lebanon with impunity while anti-Syrian Christian militias in central Lebanon expanded their positions with Israeli logistical help.

When Syria, the Arab-appointed "peacekeeper" force in Lebanon, felt its position in Lebanon was deteriorating, it finally struck hard at key Christian positions on the Sannine mountains, commanding the Christian heartland.

Israel, pressed to prove its credibility to its endangered Christian allies, last week shot down two Syrian helicopters taking supplies to the mountains. Israel had previously refrained from directly attacking Syrian units in Lebanon, apart from several dogfights. Syria, picking up the gauntlet, then moved antiaircraft missiles into central Lebanon. But this move violated an unwritten understanding with Israel in force since 1976.

The danger is that a loc alized attack could escalate, with both sides losing control over events.