We have all but forgotten the war with Iraq. We tend to see it now as little more than a "political mistake", like the 10p tax fiasco or Labour's mishandling of the byelection campaign in Crewe. The press and public attention have moved on and focused on more pressing matters, like the price of property.

But this mistake has killed or injured hundreds of thousands of people in a country that was doing us no harm. Mistakes of this kind - an unprovoked war of aggression - were characterised by the Nuremberg tribunals as "the supreme international crime". Mistakes of this kind would, in any regime governed by international law, see their perpetrators put behind bars for the rest of their natural lives. But the great crime of the Iraq war has been normalised and domesticated.

So successful has this process of normalisation been that in three days' time one of its perpetrators will be coming here - to Hay-on-Wye, the epicentre of polite society - to promote his book and sell some copies. I do not regret the fact that he is coming here - far from it - but I see it as a sign of the extent to which the great crime he helped to commit is viewed as an ordinary part of the political process.

John Bolton first made the demand for a war against Iraq as a signatory of an open letter sent to President Clinton by the Project for a New American Century in 1998. In 2001 he joined the Bush administration as the hilariously-titled Under-Secretary of State for Arms Control in the State Department. He appears to have been imposed on the department by Dick Cheney, to play the role of Colin Powell's minder.

He immediately started destroying international law, successfully waging war against the Anti-Ballistic Missile Treaty, the biological weapons protocol, a treaty on small arms and light weapons and, perhaps presciently, America's participation in the International Criminal Court.

In April 2002, Bolton orchestrated the sacking of the head of the Organisation for the Prohibition of Chemical Weapons, Jose Bustani. Bustani's offence was to have offered to resolve the dispute over Saddam Hussein's alleged weapons of mass destruction, by sending weapons inspectors to Iraq.

Bolton helped to promote the false claim, through a State Department fact sheet, that Saddam Hussein had been seeking to procure uranium from Niger. He was instrumental in assembling and promoting the bogus case for war.

Only when those who help to launch illegal wars fear punishment will future governments desist from launching them. As citizens I believe we have a duty to try to deter future war crimes. So I propose that we allow John Bolton to speak here, and then carry out a citizen's arrest.

Section 24A of the Serious Organised Crime and Police Act 2005 permits any citizen to "arrest without a warrant ... anyone whom he has reasonable grounds for suspecting to be guilty" of an offence.

I do not want to advocate something I am not prepared to do myself. I was planning to stay at home on Wednesday, but I now intend to come back, listen to Mr Bolton speak, and then carry out this arrest. I hope that others at Hay might join me.