This ban will not stop us

Our leaders would undoubtedly be happy if we "moved on" from Iraq. They don't want to talk about it any more: it was a dreadful blunder, and reflects little credit on any of them. Presumably this is why the question has hardly been debated in parliament. Although the majority of the public were always against the war, this was not reflected by their elected representatives. The government behaved in a way that was transparently undemocratic but the Conservatives won't call them on it, for without their almost unanimous support the whole project couldn't have happened.

But to conveniently forget Iraq now is to forfeit the only possible benefit the war might have: the chance to rethink the dysfunctional political system that got us into this hole. If we don't, we risk digging a series of ever deeper holes. The Iraq adventure was justified as the planting of a beacon of democracy in the Middle East. Not only did it utterly fail at that, it also undermined our democracy. Appealing to our paranoia more than our vision, George Bush and Tony Blair obtained restrictions on freedoms that had taken centuries to evolve. They said these were necessary to ensure our security - a device used by authoritarian leaders since time immemorial.

Civil liberties never seem important until you need them. But by definition, that is the very time you won't be able to get them, so they have to be in place in advance, like an insurance policy. In his book Defying Hitler, the historian Sebastian Hafner describes how Germany slid into nazism. At first people laughed at Hitler and played along with what seemed trivial changes in the law. For most Germans it was all rather abstract, and they were expecting things to return to normal when Hitler faded back into obscurity. Only he didn't, and civil liberties were so compromised there was no way to stop him.

If we don't stand up about Iraq then we tacitly sanction the next steps in this deadly experiment of democratic evangelism. Those will likely include an attack on Iran, a permanent force of occupation in Iraq (probably always the intention), the complete militarisation of the Middle East, and a revived nuclear future.

Stop the War Coalition planned a march from Trafalgar Square to Parliament Square on Monday - the day parliament resumes - to draw attention to the fact that a lot of us are still thinking about Iraq and to call for the immediate withdrawal of troops. Using an archaic law (the 1839 Metropolitan Police Act), that demonstration has now been banned. Now why would that be? Stop the War Coalition has organised dozens of such demonstrations, and as far as I know not one person has been hurt. So it can't be public safety that's at stake.

No, it's the elephant in the room. This government wants to show itself as clean and new, and doesn't want attention drawn to the elephant and the mess it has left on the carpet. So it invokes an old law, to shave a little more off the arrangements by which citizens communicate their feelings to government (a process, by the way, called democracy).

It would take courage for Gordon Brown to say: "This war was a catastrophe." It would take even greater courage to admit that the seeds of the catastrophe were in its conception: it wasn't a good idea badly done (the neocons' last refuge - "Blame it all on Rumsfeld"), but a bad idea badly done. And it would take perhaps superhuman courage to say: "And now we should withdraw and pay reparations to this poor country."

I don't see it happening. But the demonstration will, legal or not: on Monday Tony Benn will lead us as we exercise our right to remind our representatives that, even if Iraq has slipped off their agenda, it's still on ours. Please join us.

Brian Eno, a musician.