President George Bush has pledged to oversee the creation of an independent Palestinian state within the next four years, as part of his campaign to bring democracy to the Middle East. This helps to explain the sharper tone he adopted at Monday's meeting with Israeli prime minister Ariel Sharon in Texas.
It seems to herald a US willingness to intervene in the negotiations more actively and critically, following the election of a new Palestinian leadership and the reactivation of the international road map towards a peace settlement.
Mr Bush told Mr Sharon that Israel should not "undertake any activity that contravenes road map obligations or prejudices final status negotiations", mentioning specifically the need to remove unauthorised outposts on the West Bank and meet its obligations regarding settlements there. The warning cuts across the assurances Mr Sharon received this time last year, when Mr Bush told him the US does not expect Israel to withdraw from all the West Bank territory occupied after the Six Day War in 1967, including major Israeli population centres there, nor to accept the return of Palestinians who left or were expelled during Israel's war of independence.
Mr Sharon hoped this visit would bolster his position against radical right-wing critics of the planned withdrawal of 8,500 Israeli settlers from Gaza this summer, the better to hold on to the West Bank. Since then, shifts in international, Israeli and Palestinian politics have made the move subject to negotiation rather than unilateral action. But the unilateral instinct remains intact, as in the recently reactivated plan to build 3,500 Israeli homes between East Jerusalem and the existing large settler conurbation at Maaleh Adumin. This would undermine the city as the capital of an independent Palestinian state with a contiguous territory. Mr Bush's criticisms apply to the project, as Mr Sharon has acknowledged.
Unless a stop is put to the creation of such Israeli facts on the ground there is no prospect of the negotiations succeeding over the next four years. But if US pressure is not applied continuously and in concert with its international partners they are likely to continue. The Palestinians, too, have obligations to accept if progress is to be made, including reining in violent resistance and creating functioning and accountable political structures.
But there must be reciprocity between the parties in coming months if serious negotiations are to begin. The meeting between Mr Bush and Mr Sharon has been a useful exercise along this way, but all will depend on whether it can deliver a real process over coming months.