Tony Blair is lucky to have John Prescott. The misfortunes of the hapless deputy prime minister dominated the front pages last week, eclipsing a series of harrowing stories from Iraq. It is a sign of our times that Prescott’s use of the country estate at Dorneywood, where he was photographed playing croquet, was given greater prominence than the roll call of death emanating from Baghdad and Basra. Blair may squirm over his deputy’s follies, but Iraq raises deeper questions about the prime minister’s judgment, with consequences infinitely more serious.

The deaths of two British men, who were gathering news for CBS, did make headlines. A roadside bomb ended the lives of cameraman Paul Douglas and soundman James Brolan, and seriously wounded their reporter, Kimberly Dozier. Reports by fellow journalists, who knew them well and who take the same risks every day, were moving. The dead men and the injured woman became for readers and viewers more than statistics because their colleagues could tell us what they were like and attest to the cheerful courage with which they did their work.

On the same day, two British soldiers from the Queen’s Dragoon Guards died when their Land Rover was torn apart by an explosion. Their deaths were not ignored but inevitably, since those writing the reports had not known them in life, we had less sense of who and what we had lost. On the day that the journalists and guards died, 40 Iraqi civilians were killed, too.

There were 11 British deaths in Iraq last month, the highest total since the fall of Baghdad three years ago. More than 100 British soldiers have been killed and the American figure approaches 2,500. The number of Iraqi lives lost is somewhere between 30,000 and 40,000.

Compared with the wars of the last century these are still small numbers. Great loss of life can be justified, even required, when the cause is right, as it was in fighting the axis powers during the second world war.

The problem in this conflict is that we have doubts about the cause and our effectiveness. Blair does not bear responsibility alone for our being in Iraq. I was among that majority of MPs who voted to send the troops there. For those who made that judgment it is painful to own up that we were wrong. But it is becoming hard to avoid the admission.

Blair’s defence is that he need never apologise for ousting the evil tyrant Saddam Hussein. But I remember well his telling parliament that if Saddam would just give up his weapons of mass destruction his regime could continue. That was the British position (although not the American one) because with our multilateralist approach we knew that we would not obtain legal sanction from the United Nations for regime change.

It does not wash for Blair to claim that toppling Saddam justifies the war. The House of Commons voted for invasion to seek out and destroy WMD. Michael Howard, the former Conservative leader, once said that if he had known then what he knew later, he could not have voted for the war on the same terms. His remark was thought to be lawyerly and weaselly. Even so, it was literally true. With the benefit of hindsight Blair himself could not have voted for the war on those terms because the premise — the existence of WMD — was false.

Even taking a wider view of our interests and those of the Iraqis, the war looks a failure. I backed the invasion because I thought the West needed to reassert its power after 10 years during which America had looked irresolute. It had made no effective response to a series of Al-Qaeda attacks that began with a truck bomb in the World Trade Center in 1993. After the decision by George Bush père not to march on Baghdad at the end of the Gulf war in 1991, Saddam provided another example of anti-American defiance that had gone dangerously unpunished.

For those who took my view, to feel justified now we would have to show that western willpower had been effectively reasserted. The early signs were encouraging. Colonel Gadaffi of Libya, whose agents had blown up an airliner over Lockerbie in 1988, renounced terror and shook hands with Blair. But after three years the invasion of Iraq has proved counter-productive.

The United States has shown itself incapable of controlling Iraq or Afghanistan. As the public becomes disillusioned with the war and as the president’s ratings plummet, the world has fresh reasons to doubt America’s willpower. Its military appears overstretched and the idea of another war of conquest is implausible.

Iran is certainly not cowed by having more than 100,000 US troops next door. Saddam’s forces caused it much greater concern. Tehran pursues uranium enrichment with a new militancy. America denounces it as the premier state sponsor of terror. Yet now the White House is willing to enter direct talks with that regime, even as Iranian agents and explosives are probably killing American soldiers in Iraq.

It is a vivid illustration of US weakness, although the new démarche is nonetheless the right thing to do. America has given up a policy of pre-emptive strikes against regimes that pose a threat in favour of a cold war-style strategy of diplomacy, economic sanctions and containment.

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