Israel's goal of pressuring the Lebanese government to pressure Syria into pressuring Hezbollah to stop attacking Israel appeared to have backfired.

First, Israel's accidental bombing of the U.N. base in southern Lebanon last week that killed nearly 100 Lebanese civilians ignited worldwide criticism of the Israeli operation as an overreaction and sparked U.N. condemnation.

Then Syrian President Hafez Assad, who had been politically isolated until now, entered the spotlight and played the role for all it's worth.

With U.S. Secretary of State Warren Christopher heading a shuttle mission to bring about a cease-fire, Assad took full advantage.

On Tuesday he first canceled a meeting with Christopher, who had flown to Damascus to meet him, saying the U.S. secretary had arrived 20 minutes later than expected and conflicted with a Syrian state dinner with Pakistani Prime Minister Benazir Bhutto.

Christopher returned Wednesday to Syria, then drove to a meeting with Lebanese Prime Minister Rafik Hariri in eastern Lebanon — as Israel stepped up its bombardment of Hezbollah forces in the south.

Meanwhile, the foreign ministers of France, Russia, Ireland, Spain and Italy were also in the region this week, attempting to work out a solution to the fighting.

Israeli Prime Minister Shimon Peres, however, said Israel preferred dealing with one diplomatic source.

"We can have many fronts, but one channel. If there will be more than one channel, there will be total confusion," Peres said.

By midweek Israeli and U.S. officials spoke optimistically about a potential U.S.-brokered agreement.

The backing of Syria, which maintains some 40,000 troops in Lebanon and which controls Hezbollah's main supply routes, is crucial for any truce to hold.

Christopher's shuttle mission was prompted by Israel's shelling last week of the U.N. post, which reportedly came after an Israeli commander in southern Lebanon mistakenly believed his unit was under Hezbollah fire from near the base.

Israel has appointed a commission of inquiry to investigate the bombing, and Israel Defense Force officers met with U.N. peacekeepers last week to express their regret for the casualties.

Meanwhile, Peres said Iran was sending more Katyusha missiles to continue striking at northern Israel and eventually undermine his re-election hopes.

In an unconfirmed report, a Jordanian newspaper said Iran has supplied as many as 4,000 more rockets to Hezbollah via routes controlled by the Syrians.

Hezbollah fired close to 500 Katyusha rockets at northern Israel since the operation began, causing more than $10 million in damage, Israel said.

IDF sources maintained the Katyusha attacks had slowed considerably as a result of Israeli air force and artillery attacks on launch sites.

Israeli jets this week also hit the stronghold of the Popular Front for the Liberation of Palestine-General Command organization, headed by Ahmed Jibril in Na'ameh, some eight miles south of Beirut.

The PFLP, which has its headquarters in Damascus, is closely tied to Hezbollah and has also attacked IDF and its allied South Lebanese Army targets inside the security zone.