In an event co-sponsored by the thinktank Ekklesia, the Archbishop of York last night launched an outspoken assault on US and UK policy in Iraq, warning of the dangers of "militarism out of control", reports the Guardian newspaper.
Dr John Sentamu called for the UN to be given a central role in mediating global conflicts.
He said in the speech to CHIPS (Christian International Peace Service): "A scant regard for international law carries a high price, not only in terms of political uncertainty but more importantly in the body count which daily increases in those places where unilateral military action has proved so costly.
"In the short term such actions lead to quick victories, which make for great headlines. But the hard work of reconciliation, the hard labour of peacemaking ... never made it to the drawing board of those planning the invasion.
"We only have to look at the mounting daily death toll in Iraq to see the effects of military action without a concerted UN backing, where the consequences of militarist solutions play out against escalating sectarian and anti-western unrest ..."
In August, the archbishop fasted for international peace for a week, camping in a tent at York Minster, in response to the televised pictures of the war in Lebanon.
The event marked the 40th Anniversary of the Christian International Peace Service (CHIPS).
CHIPS works for peace and reconciliation in areas of conflict and tension around the world. Its emphasis is on grassroots approaches recognising that while political solutions are important, without the engagement of individuals and communities, real and lasting peace may be impossible to realise.
A 'relational organisation' it tailors its approach to particular situations to inspire and motivate local people to build peace in their communities. CHIPS supports teams of Christians to undertake practical projects which foster positive interaction, increase trust and reduce enmity between opposing groups or individuals.
CHIPS is a member of the Coventry Cathedral Community of the Cross of Nails.