When President Bush set foot in Israel today for the first time in a decade, he may have been tempted to believe that peace could finally be at hand in that tortured land.

On the apron of Ben Gurion Airport, Israeli leaders and dignitaries turned out in force to pay their respects to the man regarded as the Jewish state’s most powerful supporter.

Tomorrow, Mr Bush will receive a no less respectful reception when he travels to the West Bank to be greeted by President Mahmoud Abbas and the Palestinian leadership.

Unencumbered by domestic issues and free to focus on America’s top foreign policy priority, the President will have calculated that he has just over a year to deliver what has eluded successive presidents before him.

The prize would be huge. For 40 years the Holy Grail of US diplomacy has been the search for an Arab-Israeli peace agreement, that would see Israel living side-by-side with a Palestinian state and in return recognised by the broader Arab world.

The parameters of the deal were set out by Mr Bush five years ago at the Red Sea resort of Aqaba, when Ariel Sharon, the former Israeli Prime Minister, and Mr Abbas signed up to the “road map” for peace.

The initiative was given a fresh boost in November when Arab states, Israel and world powers gathered in Annapolis to press home the urgency of a deal.

The Bush Administration believes that a Palestinian state can be born by the end of 2008 if the two parties now engage seriously in negotiating the thorny issues of future borders, Jewish settlements, the status of Jerusalem and the fate of Palestinian refugees.

The reality on the ground, in places the presidential cortege will not be visiting, is very different. The Palestinian lands, which would form the future state, are divided by Jewish settlements and the Israeli security wall. Their inhabitants are trapped in a no man’s land that can barely support a poor rural economy, let alone become the foundation for a thriving sovereign state.

The Gaza Strip, a sizeable chunk of Palestinian territory, is now completely in the hands of the Islamic militant movement Hamas, whose fighters are engaged in daily rocket duels with the Israeli military. It is far more likely that the two sides will go to war in this crowded strip before it becomes part of a stable future Palestine.

The fragile security situation is matched by the frailty of the key players in the process. Ehud Olmert, the Israeli Prime Minister, remains weak and unpopular and could be forced out of office later this month with the publication of a report into his handling of the disastrous war in Lebanon in 2006.

As for Mr Abbas, he has failed to turn the Palestinian Authority into a viable government in spite of millions of pounds in aid and support from the West.

During his tenure the balance of power has shifted to the militant Palestinian cause, generously supported from countries like Iran and Syria, who reject any notion of a peace deal with Israel. Moderate Arab states like Saudi Arabia, Egypt and Jordan stand ready to help, but none is likely to engage deeply in a process that seems doomed.

Finally, there is the problem of Mr Bush’s role. Middle Eastern leaders are past masters at sniffing out the strengths and weaknesses of those who visit their lands.

The point was graphically illustrated by Iranian gunboats which harassed US Navy warships travelling through the Gulf on Sunday. A year ago such a provocation would have been unthinkable because it would have met with a punishing response. Many will have concluded that power is ebbing away from Mr Bush by the day as America focuses on choosing its next leader.

Certainly he would do well to remember the experience of his predecessor, Bill Clinton. He tried and failed to clinch a peace deal in the dying days of his administration. Instead of an historic agreement at Camp David, the region was left with another conflict at the cost of thousands of lives.

Mr Bush’s already tarnished record in the Middle East could suffer even more if this delicate process is mishandled.