As I write, the UN continues its deliberations about what kind of resolution might be possible to support and effect a ceasefire in Lebanon. The optimistic gloss is that this could be achieved 'in a few days', though the organisation of an international peacekeeping force is likely to take several weeks.

A few days is a long time in the Middle East at the moment. Not only because of the uninterrupted cycle of slaughter, but because of the mounting humanitarian crisis in the region - in Gaza and the West Bank as well as in Lebanon. If an immediate ceasefire is going to take a few days to implement, that will still mean an unpredictable number of Israeli and Lebanese civilian deaths and further damage to the infrastructure of Israeli, Lebanese and Palestinian society. It makes any prospect of a sustainable peace settlement more remote. The longer we wait for a ceasefire, the harder a ceasefire becomes - let alone a more comprehensive settlement.

That is why voices in the region, notably from some connected with the Middle East Council of Churches, are increasingly concentrating their efforts on some short-term goals. There have been detailed proposals for a very brief ceasefire (seventy two hours, for example) designed to allow humanitarian aid to be delivered to areas that are currently unreachable. World Food Programme convoys are stopped and other vital supplies are being held back by blockade or bureaucracy. Hospitals are struggling to cope with uncontrollable levels of civilian casualties. Even if a complete formal ceasefire proved impossible, even for a short and defined period, a gesture like the lifting of the naval blockade for the delivery of humanitarian supplies would be a target worth working for.

There have also been appeals to Hezbollah to give assurances about the welfare of the captured Israeli soldiers to their families. There is a clear perception that even the remotest possibility of an exchange of prisoners would depend on some initiative that would break a deadlock of absolute mutual mistrust. Assurances from Hezbollah, no less than the suspension of the naval blockade, could, it is argued have this effect.

A good deal more in similar vein is coming from the churches in the Middle East (who, it's worth remembering, have their own concerns about a Hezbollah 'victory'). It is time we listened harder to them. And what is important here is the motivation of these voices. They are saying with the greatest of clarity that every hour that passes is making the post-conflict prospect more and more unbearable - to the point where even the briefest and most nominal interruption of the mutual carnage becomes disproportionately significant.

And the underlying problem, identified by one or two commentators in the USA, is that both sides in the Lebanese conflict are playing for very high stakes - on one side, decisive victory over what is seen as an engine of terror, on the other, a decisive humiliation for Israel, with regional repercussions in the balance of power and a dramatic strengthening of certain elements in the Islamic world. In that sort of climate, the question of who blinks first becomes very fraught indeed - so that the gestures of goodwill suggested by the Christian leadership of the region do not at first glance look all that probable.

But this means that, on both sides, the comprehensive ravaging of an infrastructure is seen as a price worth paying for an imagined future stability. Hezbollah directly and deliberately targets civilians in Israel and apparently regards the lives of Lebanese civilians as counters to be deployed in their strategy; Israel risks treating the Lebanese population as if they were all de facto collaborators with Hezbollah. Both act like this because the prize is so temptingly comprehensive. Yet the irony is that the only clearly visible effects are the returning of Lebanon to a chaos from which it had begun to escape and the continuing exposure of Israeli civilians in the border area to indiscriminate attack, which shows no sign at all of lessening. Those who are rightly anxious about Israel's security have to ask about the cost of so dangerously unstable a neighbour. The big prize of some really decisive solution, some transforming victory for one value system over another, is simply being made more and more unattainable by the tactics being used. It is a lesson that could be applied, in a different degree, to the whole rhetoric of the war on terror.

The ethical tradition that has developed around the conduct and aims of war is profoundly discouraging about definitive solutions that will justify any amount of interim suffering and devastation - which is why terrorist tactics are always immoral without qualification. But even in the deployment of legitimate defensive force, one of the moral criteria applied historically to the judgement of any such action is whether it has in view attainable, limited and realistic goals to be secured by any engagement of force. And this implies that a conflict fought on an all-or-nothing basis, rather than looking to measurable advantages and negotiated adjustments of interest, is going to be morally problematic. Consciously to create a civil vacuum in the hope that it will guarantee total victory is to court both practical and moral defeat in the long run.

So one of the middle-to-long term issues for any UN intervention will be what kind of peace is expected to emerge if a ceasefire is negotiated - and who takes the responsibility for anything that looks like a 'common security' solution, preserving the integrity and legitimacy of civil society and government in Lebanon and giving no possible handle to the rhetoric of groups (or nations) that challenge Israel's right to exist (the Arab Summit of 2002 - in Beirut, ironically - attempted to put down a positive marker on this). Some of the Middle Eastern commentators I have been discussing have outlined a process by which Israeli withdrawal from the disputed Shebaa Farms territories (on the guarantee from Syria that Lebanese sovereignty here is recognised) matches a 'decommissioning' of Hezbollah units and their absorption into the Lebanese security forces under international monitoring. It is again a move that does not currently look easily achievable. But only something like this will make any useful contribution to a proper strategy for a law-governed outcome in the region. And that is the only goal worth working for.

A law-governed situation is one in which interests and conflicts are argued, negotiated and balanced out, with no permanent, unassailable winners and losers. At the moment, what we see is dangerously close to lawlessness in the strict sense, a disregard for present chaos and pain in the name of a future that will justify everything. The Abrahamic faiths are all committed to law because none of them can accept that consequences alone justify actions. So we need to hear more from leaders of all these faiths in support of law as well as of immediate humanitarian action - in support of short-term improvements, pragmatic means of resolving injustices, civil procedures for discovering common goals, however limited, acceptance of interests that are more than 'reasons of state'. And we need to hear more from jurists of all backgrounds in the mapping out of what a ceasefire and an international presence will be seeking to make possible in Lebanon and in the region.

And meanwhile, we could do worse than spend a moment listening to the most immediate pleas from those on the ground. A statement from Hezbollah about its prisoners, an easing of the blockade to guarantee safe passage for WFP convoys and supplies for the hospitals of Lebanon and Gaza - these are not huge and complex matters. But if they save even a handful of lives, they are not wasted. And they will represent just a small sign that somewhere there is a shared future to be negotiated for the ordinary people of the region, Israeli, Palestinian or Lebanese.

© Rowan Williams 2006