Saddam Hussain's regime was of course defeated in April 2003. However, since then most central and some northern areas of Iraq have seen an escalating guerrilla-style war of resistance being waged against the occupying forces and their proxies. Even the south, which has been relatively free of sustained conflict, has seen two major armed uprisings in the last two years. British troops haven’t been directly involved in most of the major operations, but their presence provides crucial support for the US as it wages its counter-insurgency war. When George Bush famously announced the end of the war in April 2003 around 100 US troops had been killed in Iraq. This month the number reached 1500. Some "post war" period.

Certainly the occupiers are not involved in a traditional state v state conflict, with pitched tank, naval and aircraft battles. They are however fighting a large number of irregular forces, which clearly have a significant degree of support amongst many parts of the population. The US presents this resistance as being simply a mixture of old Saddam supporters and religious extremist Sunnis who are trying to provoke civil war with the Shia majority by unleashing suicide bombings on civilians. But many commentators now believe that such terrorist elements are in the minority, outnumbered by forces who concentrate their (less-reported) attacks mainly on the US military and are united by no more than the desire to see an Iraq free of foreign control.

The response to the rebellion has been brutal. In recent months air strikes have been called in on numerous Iraqi cities, including Mosul, Ramadi, Samarra and Falluja. No one knows how exactly many Iraqis have been killed because, as the US military says, "we don't do body counts". The best estimate so far, published in the British medical journal The Lancet says that probably well over 100,000 Iraqi civilians were killed as a result of the conflict between March 2003 and October 2004.

When Falluja was attacked in November 2004 Lieutenant Colonel Paul Newell, battalion commander with the US forces told the New York Times “This is the first time since World War II that someone has turned an American armoured task force loose in city with no restrictions. Let’s hope we don’t see it again any time soon.” Newell wasn't joking. After softening the city up for days with a sustained artillery barrage US troops attacked on 8 November 2004. Associated Press reported the experiences of its photographer, Bilal Hussein, a Falluja resident:

“Heavy bombing raids and thunderous artillery shelling turned Hussein’s northern Jolan neighbourhood into a zone of rubble and death. “I saw people lying dead in the streets, wounded were bleeding and there was no one to come out and help them. There was no medicine, water, no electricity nor food for days. US soldiers began to open fire on the houses…so I decided that it was very dangerous to stay”. Hussein planned to escape across the Euphrates river. “I decided to swim…but I changed my mind after seeing US helicopters firing on and killing people who tried to cross the river”. He watched horrified as a family of five was shot dead as they tried to cross."

Lieutenant Colonel Newell said that the residents of other cities should conclude, “this is what happens if you shelter terrorists”. The irony of describing others as “terrorists” when his own forces were using massive and unrestricted violence to teach civilians a lesson was apparently lost on him.

Falluja remains in ruins to this day. Formerly a city of 300,000, it is now reduced to dust and rubble. Try telling its remaining citizens that the war's been over for two years.

Even if there was no weapons of mass destruction, Blair lied and so on, surely Saddam's been deposed, Iraq is becoming a democracy, and these are pretty good outcomes? Isn't Iraq better off now? Why march against that?

For now, lets leave to one side the obvious point that “better than Saddam” is some way beneath the level of splendour that Bush and Blair promised for the Middle East as the fruits of their crusade. The truth is that Iraq is now in an extremely grave condition, nearly two years after a US-led coalition of wealthy and powerful nations invaded the country.

Since the invasion infant mortality has increased, more children are malnourished – now 3 in 10 – and acute malnourishment among children has almost doubled. Over 700 primary schools have been damaged by bombing, with more that 200 burned and over 3,000 looted. The south is littered with large amounts of the depleted uranium, used in US and UK ammunitions and known to cause respitory problems, kidney problems and cancer. Iraq holds the world’s second largest oil reserves yet its economy is a train-wreck, with unemployment sent soaring up to 67% as a result of US “shock-therapy”.

But the number one concern for Iraqis is security. According to Patrick Quinn of AP:

"By day or night, Baghdad has become a cacophony of automatic weapons fire, explosions and sudden death, its citizens living in constant fear of being shot by insurgents or the security forces meant to protect them. Streets are crammed with passenger cars fighting for space with armored vehicles and pickups loaded with hooded and heavily armed Iraqi soldiers. Hundreds of bombs in recent months have made mosques, public squares, sidewalks and even some central streets extremely dangerous places in Baghdad. On Haifa Street, rocket-propelled grenades sometimes fly through traffic. Rashid Street is a favorite for roadside bombers near the Tigris River.”

The state of anarchy makes media reporting from anywhere outside of Baghdad close to impossible.

As for democracy, while much talk has been made of it this was never a matter of urgency for the US. Former governor Paul Bremner had intended to drag out American rule indefinitely, but the Shia leader Ayatollah Ali al-Sistani brought mass demonstrations onto the streets in favour of elections, forcing the hand of the occupier. When the elections came turnout was high and voters jubilant in the largely peaceful Shia-dominated south, but almost nobody voted in the war ravaged, predominantly Sunni centre, leaving a government completely unrepresentative of Iraq’s cultural make-up. A serious election campaign was practically impossible, with candidates subject to death threats and unable to reveal their identity to voters as a result. Unlike in elections in East Timor and Palestine for example, international observation to guarantee a free and fair vote was nowhere to be seen. If any countries other than the US and the UK had presided over these elections they would have been held up to international ridicule.

Now, behind the newly elected government, lurks the might of the US military. It’s something of a stretch to describe a country with tens of thousands of foreign troops on its soil, bombing its towns and cities and killing its people, as free, sovereign and democratic. However, at this point we should recall that the US and the UK backed Saddam while he committed all his worst atrocities and maintained a sanctions regime upon Iraq in the 1990’s that UN officials described as genocidal, which killed over a million civilians; 4,000 under-fives per month according to UNICEF. The idea that the welfare and freedom of Iraqis can be entrusted to these governments is a contentious one, to put it rather mildly.

If Iraq's in the state you say it’s in wouldn't it be irresponsible to leave now? Wouldn't the country descend into anarchy and civil war, and possibly be taken over by religious extremists? Shouldn't the troops stay to provide the Iraqis with security?

Since the lack of security stems in no small part from the war being waged between the resistance and the occupying forces, its no great leap of logic to suppose that if the country were no longer under occupation a good deal of the violence would cease. The occupation is to an enormous extent the cause of the violence, not the solution. That much seems blindingly obvious. In fact the resistance has been responsible for far fewer “collateral” casualties than the occupiers.

One of the central questions regarding the competence of the US to provide security is that regarding its well documented practice of sexually torturing prisoners. The latest of many chilling stories to emerge is that of resistance figures broken during interrogation by being forced to watch their children undergoing torture. Its doubtful that such methods inspire feelings of security and well being amongst the population.

After a US/UK withdrawal, security provision would of course be required, at least until such time as the nascent Iraqi forces were ready to take on the task. A plan for such a force has existed for some time; made up of Muslim troops under politically neutral command, or under the command of the Iraqi Government, and so more acceptable to the population. In the absence of US/UK forces it might be politically possible to introduce such forces in greater numbers than was originally proposed. This conciliatory measure could go a long way to cooling the temperature in Iraq and securing the country. But the plan was rejected out of hand by the US, which in itself gives an indication of their true priorities.

Even if I accept what you say, why should I spend my Saturday afternoon going on a march about it? What's that going to achieve? The demonstration in London before the war was enormous and it didn't change a thing.

The first and most important reason is that we all share responsibility for what our country does. We live in a relatively free and democratic society. We’re not prevented by the state from speaking out or organising in opposition to our government. Whether by voting or by abstaining, by taking direct action or by staying at home, the net result of all our political activity or non-activity is the government of this country, no matter how poor our electoral system or how narrow our choices. Britain has taken a central role in the invasion of Iraq, is the US Government’s strongest ally on the world stage, and is plainly on the wrong side at this point in history. Since the way Britain conducts itself is literally a matter of life or death, any contribution we can make to influence how our country behaves, however small that contribution may be, is something to be taken very seriously indeed. Iraqis, for example, don’t have the luxury of being apathetic about what our government does.

Beyond Iraq, the US has made it clear that aggressive militarism is its new modus operandi - with action being considered against Syria and Iran - and that international law is something it holds in utter contempt. The question here is whether we’re content for our country to help push the world yet further in this direction, and accept responsibility for the disasters that ensue.

Without direct action the world would be very different. Its victories include the abolition of slavery, the vote, women’s suffrage, Indian independence, and ending apartheid to name but a few. In each case victory was not handed down by the powerful through sheer generosity, nor was it ever won through a single afternoon’s demonstrating, as easily as flicking a switch. It was won by ordinary people organising and acting and repeating their actions, escalating the pressure on those governments by raising the political costs of their crimes. The demonstration this Saturday won’t change things by itself, but it will certainly makes its contribution. We can’t be sure of how much we’ll achieve by joining the march, but we can be absolutely certain of how much we’ll achieve by staying away.