BBC News Online looks at what the Middle East roadmap says and what the various parties can do to help - or hinder - the search for peace.
Click on any question below for more information.
What exactly is the so-called roadmap and how has it been doing?
Launched in June 2003, it was intended to be a goal-driven, phase-by-phase route to ending the conflict between Israelis and Palestinians within two years. It was also meant to have specific target dates, benchmarks and reciprocal confidence-building measures built in.
The plan was pieced together by diplomats from the United States, Russia, the European Union and the United Nations, and was amended after consultations with Israelis and Palestinians.
Though still backed by the US, the roadmap has failed to take off since its launch.
The Palestinian militant groups declared a temporary ceasefire, but this has not held. The suicide bombings, though less frequent, continue.
Israel has reneged on commitments to pull down un-authorised settlements and has continued with its policy of assassinating political and military leaders of militant groups.
The Palestinian Authority is also into its second prime minister with no sign that Yasser Arafat is ready to take a back seat.
What are the main stages in the plan?
Phase 1 (originally intended to take place by May 2003): End to violence against Israelis and Palestinians; Palestinian political reform; Israeli withdrawal and freeze on settlement expansion; Palestinian elections
Phase 2: (June-Dec 2003) Creation of an independent Palestinian state; international conference and international monitoring of compliance with roadmap
Phase 3 (2004-2005): Second international conference; permanent status agreement and end of conflict; agreement on final borders, Jerusalem, refugees and settlements; Arab states to agree to peace deals with Israel
How important is US involvement in the process?
Very important - the US is the only country with sufficient leverage to get things moving.
Other countries and mediators can make some progress but the Israelis do not trust the roadmap's other backers - the European Union, Russia and the United Nations.
The Palestinian leadership has also put its trust in American mediation, despite the fact that Washington is Israel's main ally and military backer.
That is why most observers believe a deal is only possible with active American involvement.
US pressure has been patchy, and Washington's attention has been firmly on Iraq.
Would the proposed Palestinian state be viable?
The roadmap explicitly aims to make it so, but many Palestinians question whether Israel is really prepared to allow such a state to come into being.
For the state to be viable it will have to have territorial contiguity, which will mean Israel dismantling most of its settlements in the West Bank and Gaza. Palestinians who support the so-called two-state solution say all of the land captured by Israel in 1967 must become the future Palestine, so that means all the settlements will have to go.
Add to that the need for a state to control its own borders and airspace, as well as its water supply and other natural resources, and it is clear that the viability of a future Palestinian state will be a fraught issue.
If the roadmap were implemented, how would it affect Israeli settlers and Palestinian refugees?
These are two of the most difficult areas of dispute - one group because they won't be moved from their current location and the other because they insist on returning to homes they left decades ago.
The roadmap delays final agreements on both issues until the end of the process. In the meantime it calls for an initial freeze on settlement activity and dismantling of settlements built in the last two years.
Mr Sharon has said repeatedly now that Israel would have to make "painful concessions" for "true peace, real peace, peace for generations". Many observers interpreted that as a willingness from Mr Sharon - an architect of the whole settlement project - to dismantle settlements, but it is not clear how many he will dispose of.
As for the refugees, Palestinians see the issue as one of human rights and justice, while Israel fears it will be unable to survive as a Jewish state if it allows millions of Palestinians to settle within its borders.
The roadmap calls for "an agreed, just, fair and realistic solution" to the issue - something that has proved impossible to realise until now.