So now we know: this is what soon-to-be-ex-presidents do. Bill Clinton spent his final hours in the White House trying to patch together a deal between Ehud Barak and Yasser Arafat and now George Bush promises to spend his last year the same way, confronting the problem that has defeated successive presidents for nearly 30 years. Will he share their fate or could the road from Annapolis somehow, despite everything, lead to peace in Jerusalem?The reasons to be cheerless are too numerous to count. Start at the top, with the Americans who will preside over the process, which was given a formal launch at the White House yesterday. You don't have to succumb to the snobbish observation that, on Tuesday's evidence, Bush still can't quite pronounce the names of the leaders he is meant to bring together to have serious misgivings. The president promised his "personal commitment" to the Herculean task, yet he dashed away from Annapolis three hours after he arrived, leaving Condoleezza Rice in charge. Not a huge crime, but a sign that Bush has no intention of immersing himself in the detail as Clinton did - an effort which was surely pivotal in bringing the two sides as close as they were by the end of 2000.It emphasised what Bush had already announced, that the US will play only a hands-off role in the core, substantive negotiations. Officially, Israeli and Palestinians say that's fine, that in the end no one can end their conflict for them. But talks as complex as this need an involved mediator, one who can sometimes play referee, sometimes bridging seemingly impossible gaps - and Bush has formally eschewed that role. Incredibly, the steering committee for these core talks will be headed by the enemies themselves, with no outside broker.It's true that the US will be directly involved in overseeing the implementation of the two sides' promises under the ill-fated 2003 roadmap - the Palestinian commitment to crack down on terror, the Israeli pledge to freeze settlement expansion - but this hardly inspires confidence. Bush has made such promises before: the soon-to-be appointed US monitor, former Nato commander Jim Jones, should remind himself of the fates of the Mitchell, Zinni and Tenet missions of the recent past. Troubling too is the US designation of itself as sole judge and jury of the parties' performance. It seems as if Washington has quietly killed off the Quartet, in which it took such decisions jointly with the UN, EU and Russia.Other weaknesses were even more obvious. Missing from the Annapolis feast was Hamas, which governs one half of the territory of the future Palestinian state. They and their followers made their views known with mass demonstrations in Gaza and the West Bank on Tuesday, declaring: "The only dialogue with the enemy will be with rifles and rockets." If the men of violence were to revert to type, seeking to derail progress by launching an attack on Israeli civilians, then Ehud Olmert would respond fiercely. Several analysts I spoke to in Annapolis said Israel was "on the cusp" of retaking Gaza by force. Perhaps Olmert would be happy to keep on talking peace to Mahmoud Abbas and Fatah under those circumstances, but could Abbas do it and remain credible in the eyes of his own people? More sharply, could Abbas really topple Hamas and ride back into power in Gaza on the back of an Israeli tank? Even Israel's sunniest officials concede that Gaza is "the achilles heel" of the process.Even if Abbas and Olmert were to be allowed to get on with it, there's good reason to doubt they could reconcile their differences. Negotiators for the two men worked till 4am on Tuesday and were still haggling minutes before Bush took to the podium with a text that, in the end, dodged every point of contention. "The document could not even set out the problems, let alone state solutions," sighed the longtime Palestinian negotiator Ahmad Khalidi. It spoke of "core issues", which everyone knows means borders, Jerusalem and refugees - but they could not find the words to say so. They could agree on a process, but are a long, long way from peace.The negatives don't end there. Sixteen Arab states were present in Maryland, but hardly show signs of the deep economic and political engagement which I understand British officials believe could make a critical difference. Meanwhile, some of those at Annapolis fear the sheer hoopla - with one quarter of the world's foreign ministers present - means that there's simply a greater distance to fall when the process fails, leading to disillusion with the very notion that diplomacy can bring results.So there is no shortage of good arguments for pessimism. And yet, if only because such bleakness is bad for the soul, there are reasons not to give up just yet. Those of us who have lamented the absence of a peace process for seven long and bloody years can hardly grumble now that one is beginning. Talking is always better than not talking and certainly better than killing.The new process also has some assets worth exploiting. Sure, Olmert and Abbas are weak, but they seem to share something else too - a rapport which was entirely missing between Arafat and Barak. They are not starting from scratch, but have been talking frequently for months. Nor do they have to reinvent the wheel - the outlines of a peace settlement are already well-known, chiefly in the so-called Clinton parameters and refined in a variety of other unofficial efforts. Ariel Sharon already did much of the heavy lifting in preparing Israelis for compromise, explaining that they will eventually have to give up land. That readiness has remained in "suspended animation" ever since, says David Landau, the editor of the Israeli daily Ha'aretz. But it can be activated when the moment is ripe.The peacemakers have fear on their side too. It was fear of Iran that brought most of the Arab states to Annapolis. They reckon that progress for the Palestinians will blunt Iran's appeal in the battle of Muslim hearts and minds, pushing back Iran's regional ascendancy. That degree of international support gives Abbas essential cover. With the Arab League behind him, he won't be making historic compromises alone.Today is the 60th anniversary of the UN vote which sought to partition historic Palestine into two states, one for the Jews, one for the Palestinians. It is a resolution that remains only half-implemented. Now there is a slender chance of completing the job - and surely, despite the thousand obstacles, the world has to grab it with both hands.