It is a well-deserved irony for George Bush that his first presidential visit to Israel coincided this week with the storm of excitement produced by the unexpected outcome of the two New Hampshire primaries. Nothing could better highlight the irrelevance of the final year of the Bush presidency.

The moment at which an incumbent becomes a lame duck fluctuates in every US administration, depending on circumstances. The day on which the first votes are cast is traditionally the symbolic date, even though the race has been under way in the media for months. This year's riveting contests in New Hampshire certainly proved that true, overshadowing whatever interest there was in Bush's plans for influencing the Israeli-Palestinian conflict.

Even before the president left Washington, expectations for his visit were low. His much-trumpeted meeting of Middle Eastern leaders in Annapolis in November produced a predictably tinny follow-up. Little happened in the subsequent six weeks, and it was only courtesy to Bush that impelled Ehud Olmert and Mahmoud Abbas to meet again in advance of the president's touchdown in Tel Aviv on Wednesday and produce the blandest pretence of progress. According to Olmert's spokesman, they agreed to "authorise their negotiating teams to conduct direct and ongoing negotiations on all the core issues". Isn't this tautological statement merely a repeat of what they had already launched in Annapolis?

Bush's engagement in the world's most intractable dispute is late, piecemeal and phoney. Above all, it is one-sided. As Ghassan Khatib, a former Palestinian minister, remarked this week: "Palestinians agree that in the history of the United States, Bush is more biased toward Israel than any other American president." In any conflict, responsibility for making the largest concessions always rests on the stronger party, especially when most of the wrong is on its side. But, despite his rhetoric yesterday, Bush has not used Washington's enormous leverage over Israel to end the occupation of the West Bank and East Jerusalem.

He has not even applied pressure for an end to the expansion of Israeli settlements or the dismantling of the spider's web of roadblocks that make normal life for Palestinians impossible. A US plan for benchmarks by which to judge Israeli progress was quickly abandoned last spring at the first whiff of concern by Olmert's government. Occasional state department pronouncements disapproving of settlement expansion are not followed by measures to reflect US anger when - as happened in Jerusalem again on Wednesday - Olmert makes it clear he will continue the illegal construction of Israeli homes.

Any talk of dealing with "core issues" is meaningless without measures to reduce the daily hardships of Palestinians and end the kidnapping of hundreds of Palestinian leaders. About 40 Palestinian MPs who were seized after Hamas's election victory two years ago remain in Israeli prisons, uncharged and seemingly forgotten by Bush and other western governments. US and European policies towards Hamas remain hopelessly unjust and counterproductive.

In the first phase of the so-called roadmap that Bush boasts of having revived, Palestinians are supposed to build the institutions of a responsible state. Yet Israel and the US continue to do all they can to undermine this laudable goal by blatantly taking sides in the rivalry between Fatah and Hamas. Bush's comment yesterday in Ramallah about the situation in Gaza was one of history's most extraordinary examples of tunnel vision. "Hamas has delivered nothing but misery for Palestinians," he declared. Had he said, "My reaction and that of my Israeli and European Union colleagues to the mandate given Hamas by Palestinian voters has delivered nothing but misery for Palestinians", he would have been closer to the truth.

The human catastrophe deliberately inflicted on Gaza by western policies over the past two years is one of the great crimes of this century so far. It is especially unjustified since Hamas had been observing a truce in its attacks on Israelis for several months prior to winning the "free, fair and open elections" that the roadmap asked for. Hamas was, and continues to be, punished not for its occasional use of violence but simply for being popular. And, as often happens with sanctions, it is not the leaders who suffer, but the whole civilian population of the territory - deprived of medicine, adequate food, public services and jobs. Rather than pursuing the chimera of a final settlement that would mean nothing without Hamas's endorsement, western policy should focus on more manageable humanitarian and political goals: lifting the boycott of Hamas, promoting Palestinian unity, and forcing Israel to end its brutal siege of Gaza.

Bush is not the first US president to take an interest in the Middle East in the last year of an eight-year period of office. Bill Clinton also applied his mind to it in the dying months of his second term. Yet his performance was very different: Clinton had endorsed the Oslo process early in his first term, and showed considerable energy in pushing it forward and supporting the new Palestinian Authority.

Later, in spite of being a lame duck by the year 2000, he tried hard to get agreement between Arafat and Barak at Camp David, on a final settlement that was not loaded overwhelmingly in Israel's favour. It was a model of how American presidents can act more firmly when released from the pressures of seeking election. It only needs an effort of will for a lame duck to become the bald eagle of enlightened US power.

In contrast, Bush's current visit to the region is nothing more than a display of partisan cynicism, coupled with the hope that if some sort of interim deal is signed this year between Olmert and Abbas, it would erase Washington's failures in Iraq.

Where does that leave Palestinians as the gathering wave of US primaries prepares to reveal the last two candidates for the Bush succession? Will they have to wait as long as 2016 before President Clinton or President Obama is free enough to confront Israeli intransigence and to insist on concessions? Neither candidate has yet given any sign of breaking away from traditional pro-Israeli views of the problem, so once again Palestinians may have to wait for the eighth-year miracle. Windows of opportunity open so rarely, yet the need for early action has never been more urgent.