By Roger Hardy
BBC Middle East analyst
The Mecca agreement, reached after two days of intensive negotiations in the Saudi city of Mecca between the Palestinian factions, raises two sets of questions.
Will it end the weeks of fighting in Gaza between Hamas and Fatah fighters?
Faction leaders embrace after reaching a unity deal
And will it persuade the United States, the Europeans and other international players to resume much-needed economic aid to the Palestinian Authority?
Only if both things happen can the deal be regarded as a breakthrough. Hence the caution with which news of the Mecca accord has been greeted.
The most immediate test is for the two factions to rein in their fighters while the politicians finalise the creation of a power-sharing government.
The new government, like the present one, will be headed by Ismail Haniya, who belongs to Hamas.
Palestinian Authority President Mahmoud Abbas has given him five weeks to form a new cabinet.
So far, the world's response has been 'let's wait and see'... [though] there's already speculation of a possible split between the Americans and the European Union
Hamas will get nine posts, Fatah six and other factions four. Some sensitive posts will go to independents.
Reports from Mecca suggest Salam Fayyad, a respected technocrat, will become finance minister - a job he has held before.
An independent MP, Ziad Abu Amr, is expected to become foreign minister.
Trickiest of all is the interior ministry. Palestinian press reports indicate the job may go to Major Hamouda Jerwan, who is also an independent.
Given the violence of recent weeks, and the depth of mistrust between the two sides, further wrangling over the details cannot be ruled out.
Equally, a fresh flare-up of violence might jeopardise the whole process.
The symbolism of meeting in Mecca, within sight of Islam's holiest place, does seem to have had some effect.
AGREEMENT KEY POINTS
Ismail Haniya of Hamas remains PM
Key interior, finance and foreign ministries to be run by independents
Reports say Hamas to take nine cabinet posts, Fatah six and one each to four other parties
No explicit recognition of Israel
The promise of a billion dollars in Saudi aid was no doubt an additional incentive.
But, for the long-suffering Palestinians, the real prize is the resumption of international aid.
And that is not assured.
Much of the wrangling in Mecca was over the word "respect".
Rather than agree to "commit itself" to existing Israeli-Palestinian agreements, Hamas insisted it would merely "respect" them.
The international community has demanded much more: the Islamist movement must recognise Israel, renounce violence and formally accept existing peace agreements.
Wait and see
The Mecca accord is embodied in a letter from Mr Abbas to Mr Haniya. It states: "I call upon you to respect international resolutions and the agreements signed by the Palestine Liberation Organisation."
But what does that actually mean?
So far, the world's response has been "let's wait and see".
Nevertheless there is already speculation of a possible split between the Americans and the European Union.
Some Europeans may argue the situation is so bad in the Middle East that it makes sense to lift, or ease, the embargo - and do business with the new government once it is up and running.
The Bush administration will be reluctant to take that course.