The Archbishop of Canterbury condemned policymakers for failing to consider the cost of the Iraq war as he led a memorial service today for the 179 British personnel who died in the conflict.
In a nuanced but powerful sermon, with Gordon Brown, Tony Blair and the Queen in the congregation, he warned against the influence of the "invisible enemy", which in Christian parlance means the Devil, in determining policy during war.
"The invisible enemy may be hiding in the temptation to look for short cuts in the search for justice, letting ends justify means, letting others rather than oneself carry the cost, denying the difficulties or the failures so as to present a good public face," he said.
The Archbishop, who has previously criticised the "ignorant" and "flawed" policy in Iraq, was careful to praise efforts of the troops on the ground and commend the sacrifices made.
The main thrust of his address at the Iraq remembrance in St Paul's Cathedral, though, was the shortcomings of policymakers in Iraq.
Quoting a passage from the Bible which refers to "spiritual wickedness in high places", the Archbishop said: "Many people of my generation and younger grew up doubting whether we should ever see another straightforward international conflict, fought by a standing army with conventional weapons.
"We had begun to forget the realities of cost. And when such conflict appeared on the horizon, there were those among both policymakers and commentators who were able to talk about it without really measuring the price, the cost of justice."
The Archbishop was clearly referring to the cost in human lives, both British military and Iraqi civilian, as well as the cost to the taxpayer, which amounted to £7.8 billion.
He and others, including coroners who have held inquests into the deaths of the 179 service personnel, believe that decisions made on equipment in the early stages of Operation Telic in Iraq, notably the deployment of lightly armoured Snatch Land Rovers from Northern Ireland, led to a high number of deaths because they proved vulnerable to roadside bombs planted by Shia militia extremists.
Dr Rowan Williams's criticism of the Government's failure to evaluate the cost, and thus the risks, of putting troops in harm's way without adequate equipment is a reflection of his longstanding personal opposition to the war. The equipment issue will be one of the key elements of the official inquiry into the Iraq war announced by Gordon Brown this year.
Chapter six of St Paul's letter to the Ephesians, which was the second reading at the service, is one of the most powerful in the Bible.
The King James version renders it as: "For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places."
Dr Williams said that the campaign in Iraq, which provoked demonstrations by hundreds of thousands of protesters in Britain and around the world, would for a long time exercise historians, moralists and international experts.
"In a world as complicated as ours has become, it would be a very rash person who would feel able to say without hesitation this was absolutely the right or the wrong thing to do, the right or the wrong place to be."
With Iraq veterans and bereaved families also in the congregation, and senior royals including the Duke of Edinburgh, the Prince of Wales, the Duchess of Cornwall, Prince William, the Earl and Countess of Wessex and the Princess Royal, he offered advice on how to resist the temptations against which he warned.
"St Paul tells us to wrap ourselves around with the truth, to be defended by justice and to be impatient only for peace. These are not remote ideals for a religious minority. They are essential advice for those caught up in the anxious, fast-changing world of modern military operations, with the intense, even harsh, scrutiny they get from observers and commentators worldwide."
Also present were two former heads of the Army, Sir Mike Jackson and Sir Richard Dannatt, and Geoff Hoon, the former Defence Secretary.
The sermon echoed the controversy provoked by a previous Archbishop of Canterbury, the late Robert Runcie, who won the Military Cross during the Second World War. In 1982, at the Falklands thanksgiving service, he aroused the fury of the Prime Minister, Margaret Thatcher, when he asked the congregation to pray also for the relatives of Argentine soldiers killed in the war.
Dr Williams said: "The demanding task of winning local trust in a chaotic, ravaged society like post-invasion Iraq was one of the heaviest responsibilities laid on armed personnel anywhere in recent times.
"Many here will know just how patiently and consistently that work was taken on.
"The moral credibility of any country engaged in war depends a lot less on the rhetoric of politicians and commentators than on the capacity of every serving soldier to discharge these responsibilities with integrity and intelligence."
He added: "Reflecting on the years of the Iraq campaign, we cannot say that no mistakes were ever made, when has that ever been the case?, but we can be grateful for the courage and honesty shown in facing them."
He concluded by thanking "those who have taught us through their sacrifice the sheer worth of justice and peace and who have shouldered some of the responsibility for fleshing out the values most of us only talk about".
Dr Williams has made several attacks on the Government over the Iraq war.
In December 2006 he told Radio 4's Today programme: "I am wholly prepared to believe that those who made the decisions made them in good faith, but I think those decisions were flawed.
"And I think the moral and the practical flaws have emerged as time has gone on, very painfully, and they have put our own troops increasingly at risk in ways that I find deeply disturbing."
In an article for The Times he criticised "ignorant" decisions that had put the lives of Christians in the region at risk.
The Iraq war claimed the lives of 179 British personnel, 178 servicemen and women and one civilian Ministry of Defence worker.
Mr Blair looked solemn as he listened intently to the Archbishop's address.
This article first appeared in the Times on 9th October 2009.