Although the Jordanians have followed the Palestinians swiftly to the peace table, it is not certain President Hafez al-Assad will feel under pressure to follow suit. He may harden his position, and stir up trouble for his neighbours.
Warren Christopher, the US Secretary of State, arrived in Israel yesterday, bound for Damascus, to elicit the answers to these questions. He will attempt to persuade Mr Assad to return to the negotiating table, or to open a secret channel of talks with Israel.
Progress on Syrian-Israeli peace remains blocked over the future of the Golan Heights, captured from Syria by Israel in 1967. Syria insists on an Israeli promise to withdraw from all the land before a peace deal can be discussed.
Last week Shimon Peres, the Israeli Foreign Minister, attempted to lure Mr Assad into compromise, hinting that Israel may be ready for a complete withdrawal. However, it is the decision of Yitzhak Rabin, the Israeli Prime Minister, which matters, and Mr Rabin remains silent on how far he is prepared to withdraw.
It seems clear that until the 'extent of withdrawal' is clarified by Israel, Syria will not define the 'extent of the peace' that it will offer. Western diplomats monitoring Syria fear Mr Assad may punish King Hussein for going it alone by stirring up radical Palestinian opposition groups in Jordan. Islamic leaders in Jordan oppose peace with Israel.
Palestinian autonomy is still on rocky ground. Mr Assad may also choose to augment opposition to Yasser Arafat, chairman of the Palestine Liberation Organisation, destabilising both the PLO and Jordanian peace deals. On Sunday, riots erupted in Gaza after workers were refused access to their jobs in Israel, and yesterday the Gaza Strip remained sealed off.
Mr Assad also has the power to make the Hizbollah Islamic militants in south Lebanon aggravate Israel. The Jordanian talks point to the growing isolation of Damascus, and the end of the pretence of pan-Arab co-operation. With the Jordanian-Israeli discussions, Middle East talks are taking place in the region for the first time.
Syria joined the American-led coalition in the Gulf war, while the PLO aligned with Iraq. So Damascus had great expectations of American favours in return for joining the Madrid peace process three years ago. Instead, Mr Assad is now watching from the side- lines.
There have been suggestions that King Hussein only agreed to the meetings after he got permission from Syria, and on condition the new friendship fell short of a full-blown peace treaty with Israel.
However, there is no firm evidence the King sought such a green light. The King needs American financial and military assistance, and hopes to play a role in shaping the Palestinian entity on the West Bank, which Jordan held until 1967.