Blair's beliefs on war further wounded by latest loss of respect

The point of impact is the Prime Minister’s belief in his decision to go to war in Iraq, which for all its resilience can still be wounded. And the publication of pictures showing British soldiers beating suspects and forcing them into acts of baseness will sting like vinegar in those wounds.

To understand the full significance of those pictures and the story they tell, go back to Easter. Then, news of the horrific behaviour of US troops at the Abu Ghraib jail outside Baghdad was beginning to break, and the Prime Minister suffered the greatest - perhaps the only - crisis of confidence of his career. There were other causes of the crisis too, of course, but the Abu Ghraib outrages went to the most sensitive point in Mr Blair’s normally impenetrable moral armour, the sheer ethical superiority of the British and American case compared to Saddam Hussein.

Even after Mr Blair had accepted the weapons of mass destruction argument was dead, he could still face the electorate and assure them that nonetheless, the world was a better place without Saddam. Coalition troops would establish new norms of respect, human rights and freedom for the people of Iraq.

So imagine how he felt when picture after picture spewed out of Abu Ghraib, nauseating proof that we too are capable of barbarism. The one crumb of comfort for the Prime Minister and his conscience was the distinction between British and American troops.

The semi-myth of the British squaddie as multi-cultural latter-day saint, part aid worker, part diplomat and part muscular priest, is a comforting one, not least for Mr Blair. Time and again we have been assured that Our Boys are different: they wear soft berets, not hard helmets; they befriend the local population, not kill them; they observe the laws and rules of war and peace, not violate them. That battle was won, but yesterday’s images will not be erased from the imagination so easily or so soon.

Downing Street is often keen to stress the political independence of senior commanders: remember how Mr Blair told us the decision to scrap Scotland’s infantry regiments was ultimately down to General Sir Mike Jackson as head of the army?

Well yesterday, that same politically independent general’s statement condemning any abuse by soldiers - and rather pre-empting the verdict of the court - was inspected and cleared in advance by Downing Street.

Of course, Mr Blair and the rest of us can take comfort in the thought that these examples of abuse are, as Sir Mike said, genuinely isolated incidents, the work of the proverbial few bad apples whose behaviour will disgust the vast majority of British soldiers.

Across the Arab world and in the minds of many former Labour voters, Abu Ghraib was already the final proof that the war in Iraq was the wrong thing to do. Yesterday’s events may simply act as grim affirmation of that conclusion.

To let the actions of three soldiers besmirch the reputation of thousands may be unfair. But the Prime Minister may reflect on the words of Thomas Aquinas: "For it may happen that the war is declared by the legitimate authority, and for a just cause, and yet be rendered unlawful through a wicked intention."

In other words, saying a war is just does not make it so.