The future of the Middle East peace process hung in the balance yesterday following the death of President Assad. Only last week the Syrian track - stalled since January - appeared to be on the point of revival. But now, in the words of a US state department official, everything is "up in the air" again. Talcott Sealy, a former US ambassador to Damascus, put it more strongly, describing Assad's death as a menace to the peace process. "It's really a setback," he said.

Although the president's 35-year-old son, Bashar, is regarded as modern and forward-looking, without his father's political and historical baggage, he may not have much room to manoeuvre - at least within the tight timetable set by the Americans and Israelis for the peace process.

Bashar is popular with younger Syrians but as yet he has no legitimacy. The hasty amendment of the constitution - just hours after his father's death - to reduce the qualifying age for the presidency from 40 to 34 and allow Bashar's nomination, shows how precarious his succession is.

If all goes according to plan, parliament will nominate him as the only candidate for the presidency on June 25. The people will then be asked to approve his appointment in a referendum, to be held within 90 days. Until his position is confirmed, it is unlikely that Bashar - or anyone else in Syria - will be able to make serious moves in the peace process. That in itself may well frustrate Washington's goal of striking a deal before the US presidential election.

The negotiations with Israel stalled over a few yards of land at the foot of the Golan Heights - occupied by Israel in 1967 - on the shores of Lake Galilee, with Syria insisting on access to the lake, though not the use of its waters. Various fudges have been proposed unofficially which might satisfy both parties, but Israel has been reluctant to consider them without a signal from Damascus that such a deal would bring "warm peace" between the two countries - something that Hafez Assad was probably incapable of delivering.

This view was echoed by the Palestinian peace negotiator Saeb Erekat, who said yesterday that it would be hard for any successor in Syria to be flexible in future peace talks with Israel because of Assad's uncompromising legacy.

"President Assad's legacy was that a full peace with Israel meant full withdrawal of Israel to the 1967 borders. I don't think anyone in Syria will come and accept anything less than this," Mr Erekat said in an interview.

"And therefore Israel has to realise that to make peace means it has to withdraw to the June 1967 borders on both the Syrian and Palestinian tracks," he said.

Bashar might be more amenable, but whether he is prepared to adopt a different approach will depend largely on how secure he feels back home.

The Israeli government argues that it will have difficulty selling a withdrawal from Golan to the public, but this would become easier if Syria were to make a dramatic ice-breaking gesture - something like the historic visit that the late Egyptian president, Anwar Sadat, paid to Israel.

But Assad, along with many other Arabs, regarded Sadat's visit to Jerusalem as a mistake and argued that successful negotiations should end with handshakes, not start with them. "I am not Anwar Sadat and it is not my ambition to become Yasser Arafat," he was quoted as telling President Clinton last March. The Syrians also suspected that they were being stampeded into a compromise by the US-Israeli timetable merely to help salvage President Clinton's reputation.

There are two alternative scenarios of how Bashar's succession might affect the present stalemate. One is that he will need more time to consolidate his power and that he will try to avoid any decisions that, in the eyes of the Syrian establishment, his father would have disagreed with. If that turns out to be the case, the Syrian track may remain on hold for a year or two.

The other scenario is that with his more open character, he may feel that the time has come to solve the problem that dogged his father's presidency for so many years. He would, however, have to secure favourable terms with the Israelis or his domestic position would be undermined.

There is also the question of Syria's Siamese twin: Lebanon, where Bashar's initial weakness will increase pressure from Israel, and perhaps more subtly from the Lebanese, to withdraw Syrian troops. Israel has been taunting Syria on this point ever since it withdrew its own troops from southern Lebanon last month. The Syrians are also unpopular with Lebanese citizens, many of whom would like to see the back of them but are reluctant to say so in public.

Syria can, however, claim to be a stabilising influence in Lebanon - pointing out that it helped to prevent the predicted turmoil following the Israeli withdrawal. President Assad generally judged the Lebanese situation shrewdly. Whether Bashar will be able to handle Lebanon so skilfully may depend on whether he is diverted by challenges at home.