For me, like so many of my generation, the invasion of Iraq in 2003 was a formative event. Over the past eight years, I've raged against that wretched war: the lies, the deaths, the illegality, the terrorist blowback and the rest. So I never imagined that I'd end up writing a column like this one.

But I have. I felt obliged to. As Tony Blair prepares to reappear before the Chilcot inquiry into the Iraq war, the political air is thick with sanctimony and hypocrisy and a collective amnesia has descended on the illustrious members of Her Majesty's Press. Blair-baiting has become a national pastime. Few have stopped to consider whether or not our former prime minister has been wronged - and I include myself in this. Almost exactly a year ago, in the run-up to his first appearance in front of John Chilcot and fellow panellists, I wrote in these pages: "Iraq will always be Blair's war."

But I was wrong. To pin the blame for Britain's worst foreign policy blunder since Suez solely on our permatanned ex-premier - and concentrate our vitriol on Blair (or is that "Bliar"?) and Blair alone - is to exculpate all those who joined him in his Mesopotamian misadventure. It is to offer a get-out-of-jail-free card to all those stars in our political and journalistic elite who backed him, applauded him and, subsequently, apologised for him.

Blood on their hands

The truth is perhaps too horrific and shameful for us to own up to. Iraq wasn't just Blair's war. Consider the House of Commons vote on 18 March 2003. Two hundred and fifty-four Labour MPs voted in favour of military action, including every member of Blair's cabinet, with the exception of Robin Cook. Just two junior ministers - John Denham and Philip Hunt - joined Cook in resigning from the government on principle. The rest were supine sycophants or, like Blair, "liberal hawks". Some, including John Reid and Charles Clarke, even chose to heckle Clare Short when she tried to raise her concerns inside cabinet.

I remember being dressed down in the reception of the BBC's White City headquarters, as a young BBC researcher in February 2003, by Reid, who told me he knew that Saddam Hussein had weapons of mass destruction. "But what about Robin Cook's doubts?" I countered. "I don't know why Cookie's saying what he's saying, as he's seen the same intelligence as the rest of us," Reid replied. Cook died in 2005, having been vindicated over Iraq. Reid went on to be defence secretary, home secretary, a peer and chairman of Celtic FC.

Blair didn't lack supporters - nor, in our parliamentary system, would he have been able to act without such supporters. As Hansard notes, the government's motion for the emergency Iraq debate in parliament on 18 March 2003 was tabled by the prime minister; the deputy prime minister, John Prescott; the chancellor, Gordon Brown; the foreign secretary, Jack Straw; and the defence secretary, Geoff Hoon. They all dipped their hands in blood.

Yet how many of them have been held up to the same scrutiny - or exposed to as much ridi­cule and abuse - as Blair? Take Hoon. The dead-eyed defence secretary went on to serve as leader of the Commons, chief whip and transport secretary. It wasn't until March 2010 that he had his comeuppance: Channel 4's Dispatches secretly recorded his attempts to find ways of translating his "knowledge and contacts" into "something that frankly makes money".

Others continue to prosper. Prescott has time to tweet to his 41,742 followers on Twitter, star in television ads for moneysupermarket.com and regale passengers on board a Cunard cruise liner with risqué anecdotes about his affair with his secretary. But the former deputy PM has yet to find time to apologise for his role in the Iraq imbroglio. Prezza did tell the Chilcot inquiry last summer that he thought the intelligence dossier against Saddam published in September 2002 consisted of "tittle-tattle" - but he chose not to resign over it, nor even to express his doubts to the prime minister.

Then there are the Tories. Iain Duncan Smith, the sainted Work and Pensions Secretary and committed Christian, was then leader of the Conservative Party and went far beyond Blair in exaggerating the threat from Saddam. In September 2002, having been briefed by friends

in the Bush administration, Duncan Smith claimed that Iraq was developing ballistic missiles that would have "the capacity to strike most of Europe, including London". Had the gung-ho IDS not rallied his Tory troops behind the government, Blair would not have had his crucial Commons majority in March 2003.

Case for action

What of the media? The truth-tellers of Fleet Street were eager to sound the trumpet of war. Most newspapers - the Telegraph, Times, Mail, Sun, Express, Star, Sunday Times, Sunday Telegraph, Observer - lined up behind the invasion of Iraq and promulgated lies and half-truths about Saddam's links to al-Qaeda, WMDs ready for use in 45 minutes, and so on.

The highly paid British commentariat was dominated by armchair generals and laptop bombardiers, both young (Johann Hari) and old (William Rees-Mogg), both left (Nick Cohen) and right (Matthew d'Ancona). Most seemed unable to tell a Sunni from a Shia but they enthusiastically made the case for military action in columns, leaders and broadcast interviews. Meanwhile, according to a Cardiff University School of Journalism study, the "liberal" BBC displayed the most "pro-war" agenda of any broadcaster - a charge backed by a separate study for the Bonn-based Media Tenor group.

Blair isn't innocent. He was prime minister at the time and, indeed, the prime mover behind the conflict. But he had help, and lots of it. It's time to hold all of the Iraq hawks to account, not just "Bliar".