Can someone remind me again, why exactly did we go to war?

My favourite TV channel (it scares me that I should have a favourite TV channel), More 4, is running a series of programs this week on the war in Iraq. More 4 is the place that Guardian readers watch TV; with a line up that includes The Daily Show, West Wing and numerous documentaries put together by Jon Snow it's not a surprise that it attracts naive idealistic yet cynical liberals like myself.

Last night they had an hour and a half long investigation on why we (the UK) went to war. It began in 2001 with (an actor playing) Tony Blair in Brighton being told to turn on the TV only for him to see the second tower being hit. From there it went through the discussions that he had with GWB and his cabinet. From the very beginning he appeared to declare to GWB that he/we (an important distinction that no one seems to pick up on) were with him/the US (another distinction we need to clarify) from the very beginning and would be with him to the end. Even when GWB states his intention to attack Afghanistan, then Iraq, and then "we will see", Blair tells Bush that "no matter waht you decide, we're with you". At which point one of his advisors asks what exactly he has just committed to.

Throughout, as increasing pressure was placed on Blair from his colleagues and from the public (not to mention France, Germany, Belgium...) he seemed increasingly backed into his corner of solidarity with the US/GWB. Every now and again GWB would through him a bone when things got tough domestically (agreeing to the second UN resolution or publicly declaring the special relationship between the US and the UK) but as time wore on the impression you got from the Blair was that he wanted to be seen to validate the inevitable US invasion of Iraq so that they weren't seen to be acting unilaterally, and thus show that it was an international response. At the same time, the impression I got of the US was that to have the Brits onside was a nice bonus, but to them it really didn't matter. At one point GWB is alledged to have to Blair that if he wants he can back out now but that he could feel free to come and help clean up the mess. Blair pauses before spluttering a reminder that he/we were with them from the beginning and would be with them till the end.

The resignations of Clare Short and Robin Cook are desparately sad.

The documentary ended with Blair alone in his office and the phone ringing. He answers it. He says "what? OK, but I thought we were starting tomorrow night?". He turns on the TV to discover that the war has started. GWB hadn't the decency to inform the other part of the 'special relationship' when the war was starting.

Looking back, I find it mindboggling that this actually happened. There seems a need to pinch myself to be sure that this is true. I'm astonished that these decisions were made and I remain frightened of what is to come. And I am upset with myself that on the day of the anti-war march I decided to play cricket. I should have been in London.

So why did we go to war? Don't tell me it was the WMD or Al Qaeda 'cos that aint it...