There's not much good to be said for those grim days in March 2003 when American and British troops invaded Iraq. But one of the few positive things to happen during an otherwise dark time was the extraordinary reaction to the war by Britain's supposedly apathetic and feckless youth.

Tens of thousands of children in the UK, myself included, walked out of school to say no to the war. At my Welsh comprehensive, 50 or so sixth formers marched out together only to be followed by a less disciplined rabble of Year Sevens, who took their protest up to the local chippie and skived off several of the day's lessons.

The action spread far and wide: in Birmingham more than 4,000 school-uniformed protestors took to the streets; in Edinburgh around 300 12- to 15-year-olds tried to occupy the castle, and in Manchester over 400 students sat in the road, peacefully blocking the traffic.

For many of us it was our political awakening. Not old enough to vote it was our first chance to try to change the world we were living in. The few hours off class were simply a bonus.

Despite all our best efforts we failed - Bush and Blair ignored us, and the 2 million who subsequently marched in London; it seemed I'd missed French for nothing.

This month, for Red Pepper magazine, I spoke to a number of young people who had joined the demos five years ago, asking them how they felt that British troops were still holed up outside Basra. Had the continuation of the war made them more politically engaged or rather increased their disillusionment?

Predictably most of them still felt as strongly; polls show that over 60% of 18- to 24-year-olds are against the war. And, to my delight, many said the issue was way too important to give up protesting.

One young activist I talked to said, that even though it might appear we had been unsuccessful, being part of the biggest demonstration ever held in the UK was not something we should quickly forget. He thought our action then had helped to stop us going to war with Iran, "It made them think before doing it again".

But, as I suspected, the events of 2003 left some with a distinct sense of disillusionment about politics and the possibility of change. One asked, "How can such an illegal, destructive, counter-productive and divisive operation like the Iraq conflict have been allowed to happen?"

When, earlier this week, I sent out a text asking for friends to join me on today's march, I received a worrying number of messages back saying, "We're marched out" or "What good will it do?" Some of these were from people who've been quite politically active in the past few years. One person even said they were playing rugby, another that they had a lunch date in Kensington. Of course I texted back, giving them the hardest possible time. Quite a few are coming now.

With no one with policies to represent us, voting turnout among the young is destined to stay low. In the 2005 election only 37% of under-25s turned out to vote. Some see cultural interventions as the way forward. With anti-war anthems like the Ugly Rumours gaining chart success and films like Nick Broomfield's Battle of Haditha getting rave reviews, perhaps this is a new way to focus and spread dissent.

But I'm firmly in the camp of not giving up on getting out on the streets. I'm disappointed, of course, that our breaking out of school didn't get us further in 2003. But I still remember the great feeling that came with making our voices heard, by doing something together. And I'm worried that if we stop marching it allows those in power to presume we don't care any more - WE DO!

Lena de Casparis lives in London, and works for Red Pepper magazine.

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