What is Washington going to do about the escalating crisis between Israel and the Palestinians? President Bush is the only person who can pull Ariel Sharon back from the brink that he seems determined to fall over. Whether Mr Bush has equal leverage on Yasser Arafat is less clear and, even if he has, it is uncertain whether Arafat has authority over the Palestinian extremists responsible for Saturday's violence. Mr Bush needs to be extremely tough with prime minister Sharon whose idea of making progress towards peace is an extremely blinkered one. Only a week ago the Mitchell Report, prepared for the US government by a highly respected former US Senator, unequivocally identified the Israeli settlements on illegally occupied Arab land as the greatest single obstacle to a resumption of the peace process and urged that, as a first step, settlement development should be frozen, including expansion for natural growth. Israel's reaction to this recommendation was, first, to say it was not acceptable and, second, to announce an expansion of the settlements, with a further 700 homes. This disdain for international opinion on the illegality of their actions follows the Israeli's disregard of several UN resolutions over the past three decades. It is difficult to understand why Israel expects the Palestinians to respect agreements and commitments when they themselves are unwilling to do so - and, in fact, are the ones acting illegally. The efforts to demonise Yasser Arafat will have no effect on the Palestinian terrorists. But with each act of repression of the Palestinians and disrespect for their natural rights committed by Israel the prospect of peace fades further into the distance. This is why President Bush must intervene urgently to prevent Ariel Sharon from taking a step too far.