Few people have felt that the decisions taken were easy or cheap. Which is why, even for critics of military intervention, just rehearsing the earlier arguments feels futile and distasteful; the weight of the cost lies most heavily on people other than preachers and commentators — the Armed Forces, the decision-makers, the people of Iraq and the region. The acute moral question now is what can carry us forward. Or, more sharply put, what can mend all the things this war and the processes leading up to it have broken?

We have to think not only about the commitment to protect civilian lives — vital, and often challenging, though it is. We must also think about strategic decisions on infrastructure. It is right to press the importance — especially in a context already as ravaged as Iraq — of strategies that seek to limit further damage to communications, water supplies, all that makes routine and emergency medical care possible. Here, we are potentially in the realm of the tragic again, since dilemmas arise when a strategy offers the promise of a speedier end to hostilities at the price of humanitarian casualties; we can only say that the moral preference must be for whatever least injures the possibilities of reconstruction.

In the longer run, we urgently need clarity about the international ownership of any political solution for Iraq, including clear commitments pointing away from “imperial” structures; we need to have road-maps not only for the future of the Holy Land but for the region overall, for its countless minorities; a clear sense of those strategies which will deliver a new energy for civil society, rooted in local loyalties and interests.

These issues cannot be put on the back burner while hostilities go forward. We must not be caught naked of ideas and clear commitments when a ceasefire arrives. And we should already be rebuilding those broken or threatened bonds of trust with allies not involved in military action, so as to draw them into fruitful collaboration in this process.

But the moral question about both international and local ownership of long-term solutions already begins to raise issues about what has so far been the greatest casualty away from the arena of war — a coherent approach to international law and to the maintenance of alliances. The US and British Governments have defended an interpretation of particular UN resolutions that has not been accepted by others; they are understandably sceptical of the idea that interpretation can be settled by the chances of a majority vote; but what then is the means of authoritative interpretation? And how are we to understand the obligations of alliances where there is insoluble dispute on finding an authoritative reading of decisions meant to bind all partners?

We have seen a situation develop where the alternatives were increasingly presented as polar opposites: open warfare or open-ended negotiation. What we seemed to lack was a compelling strategy for containing or disarming Iraq that did not involve direct military intervention. Shortly before the Azores summit, a plan appeared from American church groups which began to address these concerns; but how was it that no persuasive alternative had been explored earlier? Those in the international community most critical of war might have been expected to offer something beyond open-ended inspections (let alone sanctions).

So it is not enough to have been critical of the way war with Iraq came about. We need urgently to develop better methods of working together. Too often, the Security Council seems to be incapable of functioning as more than the sorry sum of its frequently disparate parts. Would we be helped, for example, by a standing body, more broadly drawn, and charged with formulating and clarifying options for dealing with such crises? Could we imagine such a group taking in NGOs as well as diplomatic representation, so that humanitarian relief and social reconstruction issues could be fully factored in to the main discussion?

Clearly, we have to give urgent attention to the credibility of international institutions; and this includes some hard questions for those who have been reluctant to endorse certain international juridical bodies. A clear indictment of the Iraqi regime for crimes against humanity would not necessarily have avoided war, but it would have bolstered the case for any action, military or otherwise, against that regime.

Much is made of the dangers of terror sponsored by “rogue states” — and it is a reasonable anxiety. In such an environment — though the terror itself is clearly repugnant and morally indefensible — the need for a clearly and commonly owned legitimation for action is greater not less.

The strength of the disagreement over the processes leading up to the decision to commit troops to action cannot be undone, but lessons can and must be learnt from it. We need a shared recognition of the confusions and failures on all sides — a shared repentance, to use the language of Lent — some way to help to gather us anew (and not just about Iraq) after the war.

We have to pray that the risks consciously undertaken will be less costly than some still fear; that relatively swift progress towards a settlement will follow. We must get on with addressing some of the underlying weaknesses and moral inconsistencies that have led us to a situation where our leaders have concluded that we have no alternative to war. We must not easily travel that road again.

The author is Archbishop of Canterbury

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