So, with Hamas taking control of the Palestinian Authority and its institutions, the destiny of the Palestinian people is once more in the hands of a party that believes in the dissolution of the Israeli state and in violence as a way of achieving it.
Israeli, American and in good measure European governments remain appalled and perplexed at this political earthquake. Indeed the Israelis, who are now applying the first of their economic sanctions, and Americans – planning the same – hardly disguise their ambition to subvert it. This is despite the fact that, retrogressive though it may have been, it has impeccable democratic credentials. It comes, as Ghassan Charbel put it in the pan-Arab newspaper al-Hayat, "from inside the logic of the new world order". That is to say, from the very democratisation that is the central mission of the Bush presidency, from its "war on terror" and all those sicknesses, such as despotism and religious extremism, which nurture it. This democratisation is also meant to contribute mightily to that other strategic US purpose, Arab- Israeli peace, because democratic states are said to automatically make good neighbours of other democratic states.

Yet nothing like this electoral triumph of the Hamas "terror organisation", and America’s reactions to it, could have so dramatically illustrated the blind spot at the centre of the US’s Middle East policies. Ever present, this blind spot has been brought to its apogee under the Bush administration, with its proselytising zeal on the one hand and unsurpassed devotion to Israel on the other. What US administrations seem habitually unable to see is that Palestinians, and Arabs in general, happen, like other peoples, to possess national or patriotic feelings. When these feelings are transgressed they react more or less aggressively in response. Since Palestine is the place where those feelings are most systematically flouted, it is also where democracy, as both reflection and instrument of the popular will, is most likely to be belligerent rather than peaceable.

"Democracy," said Joseph Samaha, a Beirut columnist, is not "an alternative to patriotism. It is one of its tools. The mound of western theories and sleights of hand will collapse. The mound quivered in Iraq, and Palestine turned it into ruins. Give us democracy and take resistance." Or, as Ismail Haniyeh, the prime minister-designate, put it, "We will go for arms and a parliament, for there’s no contradiction between the two."

If the Hamas assumption of power is truly a watershed, it will be an Arab and Muslim, not just Palestinian, one. It has long been said that in so far as Arabs and Palestinians ever formally accommodated themselves to Israel it was Arab despotism, not democracy, that made it possible. To be sure, Arab public opinion might have been moving away, if only in the weariness of repeated defeat, from the all-pervading "rejectionism" of the conflict’s earlier stages, but never far enough for those rulers who did make peace with Israel to do so with anything seriously resembling a popular mandate. "Israel," said Aluf Benn in the Israeli newspaper Ha’aretz, "could always do business with Arab dictators, a barrier protecting it from the rage of the ‘Arab street’. That was the basis of the peace agreements with Egypt and Jordan, Yasser Arafat and his heirs and the rules vis-a-vis Syria and Lebanon. But those days are over. Henceforth Israel will have to factor into its foreign policy something it has always ignored – Arab public opinion."

Thus, the more democracy spreads, the more militancy in Palestine will find like-minded support in the whole region. Hamas began life as the Gaza chapter of the region-wide Muslim Brotherhood movement. Nowadays Arab democracy will mean the ascendancy of Islamism and its rejectionism almost everywhere. After the Muslim Brothers, despite gross obstructionism, won a fifth of the seats in Egypt’s recent parliamentary elections, their leader said that his movement didn’t recognise Israel and proposed that the 1978 Camp David peace treaty be put to a popular referendum; they are now using their pan-Islamic connections to raise emergency funds for the sanction-threatened Palestinian people. And why is it that, just as the Americans’ well-known hankerings after "regime change" in Damascus seemed to be taking a purposeful turn, Israel suddenly took to urging them against it? Because it seemed better to preserve Bashar Assad, classical anti-Israeli nationalist despot though he may be, in his weakened condition than to unleash the demons of democracy, including the prospect of Syria’s Islamists, a powerful subterranean force, clamouring for the liberation of the Golan Heights, which for 30 years has been the quietest of all Arab-Israeli fronts, thanks to the efficacy of the despot’s repression.

Some argue that Hamas will be forced to go through exactly the same evolutionary process, from militancy to moderation, that Arafat and the secular nationalists did before it; that it already is, in fact, with its language of "truces" whose legitimacy goes back to the prophet Muhammad himself. That might well be. But Hamas has made it clear that it will not, cannot, metamorphose itself overnight as Israel and much of the west, with their conditions for engagement with it, seem to expect. That would negate much of the basis on which it was elected. So the plain fact now is that Arab democracy will not merely impede further advance in the Arab-Israeli peace process, it will endanger what the process has already achieved.

It will certainly do so, at least until America and the west, undergoing a long-overdue metamorphosis of their own, decide that Israel should become democratic too. Not for its Jewish citizens, which essentially it always has been, but for the Palestinians, at whose expense it came into being and has perpetuated itself ever since. If there is a chance of checking the resurgence of Palestinian and Arab rejectionism, it is by checking the persistent rejectionism of the other side and getting Israel to accept what in practice it never has: that very partial restitution of Palestinian national rights embodied in the Oslo accords and their two-state formula. Arafat and his now-fallen Fatah leadership persuaded his people to accept that historic concession, and reports from the occupied territories suggest that, in spite of Hamas, they still largely do. But that is not much use so long as Israel fails to honour the historically much less onerous, reciprocal concession that the world should now be urgently demanding of it.

· David Hirst reported from the Middle East for the Guardian from 1963 to 2001