Leading article: A chance for Hamas to bring Israel to the table

Of course, it is necessary to maintain a sense of proportion. The Israeli army, as of late last night, had not yet killed any Palestinian civilians in this incursion into Gaza, its first since last year's disengagement. But we cannot ignore the danger that this situation will escalate. A misplaced shell, of the sort that appears to have wiped out a Gazan family on a beach this month, could be disastrous. Firing missiles and shells into the most densely packed territory on earth is always reckless.

The Israeli Prime Minister, Ehud Olmert, has not helped matters with his threat of further "extreme action" unless Corporal Gilad Shalit is returned. Such belligerent language is not helpful to the search for a diplomatic solution. And, indeed, there is scant evidence that the Israeli government has expended much effort in pursuit of one.

The situation is complicated by a breakthrough in Palestinian politics. Earlier this week, the Hamas leader Ismail Haniya signed an agreement accepting the concept of a Palestinian state based on Gaza, east Jerusalem and the West Bank and giving President Mahmoud Abbas the authority to negotiate with Israel on behalf of the Palestinian people. This agreement is primarily about averting a civil war between the Hamas and Fatah factions of Palestinian politics, but it also contains an implicit recognition of the state of Israel, opening the prospect of future dialogue. It will, of course, take much more than this slight concession to rehabilitate Hamas in the eyes of the world, let alone Israel. But it still ought to be interpreted as an encouraging sign. Yet the response of the Israeli government has been to pour scorn on it.

Neither Mr Haniya nor Mr Abbas are in a particularly strong position at the moment. The President's political future has been hanging by a thread since Hamas' dramatic advance in parliamentary elections this year. And a power struggle is going on within Hamas too. Israel suspects that Mr Haniya is losing influence. This may be so. But the aggressive Israeli incursion into Gaza this week will make his loss of authority a certainty. What is more, by comprehensively rejecting the agreement between Hamas and Fatah, the Israeli government has further undermined President Abbas' prospects of political survival.

This Israeli intransigence - and apparent indifference to the chaos within Palestinian politics - is unlikely to further the prospects of a peaceful settlement. It also fuels suspicions that the existence of Hamas is actually a helpful get-out clause for Mr Olmert. So long as the group is in power, he can claim Israel has no partner for peace on the Palestinian side and continue with the unilateral course marked out by Ariel Sharon before him.

If Hamas were actually to sign up to recognising Israel and renouncing violence, Mr Olmert would have no choice but to come to the negotiating table. The question now is whether Israel really wants this to happen. The swift rejection of this week's Palestinian agreement, and the heavy-handed response to the kidnapping crisis, suggests not only that Israel does not feel it has a partner on the Palestinian side - but that it does not want one.