The Palestinian leader is a vital US ally and just about the only official in the occupied territories with whom Israel is prepared to negotiate.

But the White House has done him few favours of late.

Just six weeks ago, much to the delight of the Obama administration, Mr Abbas was enjoying a surprising renaissance.

A successful congress of his Fatah party, which saw popular newcomers inducted into its hierarchy, and an impressive upswing in the economy had combined to convince many Palestinians to shift their support from the Islamists of Hamas to his moderate leadership.

Then, in the space of a few days last month, it all fell apart.

Under pressure from Washington, Mr Abbas agreed to withdraw his support for the Goldstone Report, which had controversially accused Israel of war crimes during its offensive against Hamas in Gaza nearly a year ago.

When ordinary Palestinians erupted in fury and many in his own party joined the barrage of criticism, Mr Abbas reversed his decision to the fury of Israel and the irritation of the United States.

Mr Abbas's last hope of mollifying his people was to achieve a victory in his demand for a freeze of all Jewish settlements in the West Bank and East Jerusalem in exchange for a resumption of talks with Israel.

The United States initially appeared to back his position but suddenly softened its stance and lent support for an Israeli offer to simply "restrict" settlements.

Already badly weakened by the Goldstone debacle, Mr Abbas was in no position to countenance anything less than a total freeze.

Mr Abbas was marooned again and the peace process stalled.

The United States will now be praying he can be persuaded to change his mind.

Mr Abbas is known for his commitment to peace even when many of those around him are not.

He was instrumental in persuading the PLO to begin talks with Israel two decades ago and was one of the most important engineers of the Oslo Accords in 1993.

With the exception of Salam Fayyad, the reformist and pro-American prime minister, the peace making credentials of other Palestinian leaders are at best open to question.

But, however much the Americans might wish it, Mr Fayyad is not thought to have sufficient political support to win an election.

If Mr Abbas cannot have his mind changed, President Obama's ambition of completing Israeli-Palestinian negotiations within two years will increasingly look like wishful thinking.