Nicole Goodwin fought in Iraq only to come back to New York two years ago and find herself homeless. She walked the streets for several weeks, from shelter to shelter, with her one-year-old child, Shylah, strapped to her chest and their worldly possessions strapped to her back and crammed into a pram.

"What America thinks of as freedom and what I think of as freedom are two different things," Goodwin told me at the time. "I want to get a house, day care and go to college. My freedoms are small. But I can't give up ... The ideals of this country are that anybody could come back to America and make a better life ... It's a land of opportunity. In this country alone, if you put forth the effort, you can bear fruit."

At its heart the American dream has always been the triumph of possibility over probability - the idea that anyone could do anything trumps the reality that the overwhelming majority have only limited choices. Hope defeating cynicism and often masquerading as delusion.

That contradiction seems most stark when displayed on the chests of young black boys with T-shirts announcing: "Future President of America." In a country where every president has been a white man and, at current rates, one in three black male babies born in 2001 are destined to go to prison, a more realistic T-shirt would read: "Future inmate of Riker's Island." But who would want to dress their child in that? When the probabilities are so bleak and the possibilities so remote, hope and delusion can start to look like two sides of the same coin.

But if the polls are anything to go by, then those T-shirts may finally come into their own next year. Hillary Clinton leads the Democratic field with the black Illinois senator, Barack Obama, mounting an impressive challenge in second place. The most recent surveys show that if you pit either one against any of the Republican candidates, Clinton or Obama would win.

Even as Iraq has dominated America's political stage it has occupied a parallel universe in mainstream society. Military families may listen intently to every news report and live in constant fear of a visit from two uniformed officers in the wee hours. But the rest of the nation is shopping. This is the only war in modern American history that has coincided with a tax cut. "People seem to think war is OK as long as it is someone else's kid doing the fighting," says Zach's dad, Don.

Serving in it falls on the shoulders of the poor and the dark, who are over-represented in the military. And the casualties fall disproportionately on white men from small towns - like Donald Young, Zach's recently departed teenage friend. Iraq remains the number one issue of political concern, but it is rarely the central topic of conversation.

Needless to say, Iraqi deaths barely feature at all. The US military, which ostensibly came to liberate Iraqis, does not even count their corpses. So their death toll is approximate - rounded up or down by the thousand rather than counted individually. We'll never know what tender words an insurgent might send to a family member following the death of a fellow combatant, let alone the final farewell of an unsuspecting civilian slain by American troops or a car bombing. Perhaps if we did, it would help those with a limited imagination and compassion humanise the horrors of this war more easily.

Fortunately, this is not a competition. Unfortunately, there is enough misery to go around.

This is an American story. A tale of imperial overreach, military fatigue and political hubris as it affects a midwestern boy in a far away land who wants to get home. "You can tell a true war story if it embarrasses you," wrote Tim O'Brien in his Vietnam war novel, The Things They Carried. "If you don't care for obscenity, you don't care for the truth; if you don't care for the truth, watch how you vote. Send guys to war, they come home talking dirty."

The army is "about broken", said retired general Colin Powell last year - before Bush announced an escalation in troop numbers. British military standards dictate that a soldier should have two years at home for every six months deployed and that anything less than this 4:1 ratio could "break the army". American troops currently serve 15 months followed by less than a year's rest - a ratio of 4:5.

John Simkin: On page xi of the introduction you attack the sanctimony of “many liberal Europeans: “Their critique of U.S. foreign policy was often sound. But the haughtiness with which they delivered it was way off key. When their governments or citizens slam America for its brutality and imperialist pretensions, all too often they fail to do so with sufficient self-awareness or humility to see what to the rest of the world is obvious: that their nations have acted in an equally pernicious fashion whenever they have had the opportunity.”

I was surprised by these remarks. I would say all my “liberal” friends are fully aware of Europe’s imperialist past. In fact, it often goes to the heart of why they hold “left of centre” political views. Nor were they persuaded by Blair’s appeal to history with his references to Nazi Germany. They knew that the Second World War was not a war to protect and advance democracy. (If so, why did Poland and Czechoslovakia end up under the control of the Soviet Union?)

The most amazing thing about the Iraq War was those people with so-called “left of centre” political opinions who fully supported the invasion of Iraq. This was true of both the Labour Party and some notable figures in the media. What is more, so few of them have admitted their mistake by supporting the war? Some have claimed that they might have come to a different conclusion if they had known that Iraq did not have “weapons of mass destruction”. However, that was the main reason why people opposed the invasion of Iraq. Other factors such the illegality of the invasion, a grasp of the history of the region and an understanding of Bush’s real motives, were more important in the decision to oppose the war.

Gary Younge: When it comes to "liberal" Europeans attitude to US foreign policy at the moment I would say there have been two dominant strands. One has rightly attacked American foreign policy but has occasionally done so with an air of moral superiority that is laughable given Europe's own history. I see little evidence from French or Belgian criticisms of this war, for example, that would suggest that the critics would relate this to what happened in the Congo or Algeria. Instead it is understood discretely in the history of US imperialism alongside Vietnam, Korea and the first Gulf war. This isn't a competition to see who's worse but to get things in perspective. What the US has done in Iraq is not aberrant but consistent with the colonial projects of the last couple centuries.

The other, as you rightly point out, has been those "liberal hawks" who bought the whole agenda hook, line and sinker. The debacle in Iraq has embarrassed some into recanting, but many peculiarly feel emboldened. For them this wasn't a one-off mistake. They have transposed their reactionary views about the war to supporting wars on multi-culturalism and civil liberties at home. Their books have a familiar feel. "I was left wing once. I went on a demonstration and refused to buy South African fruit. Then 9/11 made me see the world in a different light. Now I feel the left has betrayed me and the causes I believe in. I stand for Enlightenment values. They are against them. I am the Left. They are not." A friend recently described these folks to me as sub-prime commentators. Their departure is really just a market correction. They were never particularly left-wing in the first place. Now they are gone. No harm no foul. We won't miss them.

John Simkin: On page 9 you write: “From the outset Bush has been putting the world ‘on notice’ and warning: ‘You’re either with us or you’re against us.’ Both he and Blair act as though there are only two possible responses to the terrorist attacks. Either you bomb one of the poorest, most famine-stricken countries in the world to smithereens, or you do nothing.” It is amazing that Bush and Blair have been able to get away with this argument that there are only two responses to this problem. How did they do it?

Gary Younge: Good question. With Bush I think it is the fear and horror of the original attack. The further away we move from the attack (that's from the same piece written on October 15th) the more difficult it becomes to evoke.

After the attacks people wanted action. Bush gave it to them. None could say he didn't do anything. I remember being in the US in October 2001.

Talking to people about the UN or other countries have responded different to injustices (Truth and Reconciliation in South Africa for example) Met with blank stares. People wanted something done. It was understandable but not very smart.

More incredible is how Blair got away with it. A Labour prime minister in a country that was not hit. There was almost a complete collapse of any link between the political culture and the political class. British people didn't want it and couldn't stop it. There was no viable party they could turn to - unlike in Spain - that would take action. In a sense he didn't get away with it because that is primarily why he had to leave prematurely. But he managed to jump before he was pushed.

John Simkin: On page 7 you write: “Even by its own standards, Operation Enduring Freedom is proving a disaster. Taking western leaders at their word, it stated aim is to defeat terrorism. A reasonable test of their war aims, therefore, would be to ask whether their actions have made a terrorist attack more or less likely.”

Like most people, I would argue that the invasion of Iraq has made the problem of terrorism worse. Living in the UK I feel far less safe from terrorist attacks than I did before the invasion. As Kenneth Clarke predicted in the House of Commons during the famous debate on Blair’s Iraq policy, terrorist attacks on London would be inevitable consequence of British troops taking part in the invasion.

However, the problem is that Americans might well feel safer from terrorism since invading Iraq. After all, they have not seen a repeat of 9/11. It is possible for Bush supporters to argue that the reason for this is that they have frightened off terrorist action because of their aggressive foreign policy. Of course the real reason is that London and Madrid were targeted because it was easier to do and that political leaders in Europe were far more vulnerable to political pressure than those in the United States.

Do you think another terrorist outrage in the United States would increase or decrease pressure on George Bush to pull out the troops from Iraq?

Gary Younge: The quote you use was from an article written on October 15th 2001. The context is important. Neither Spain nor London bombings had happened yet. I was predicting them. I think there are a few reasons why there has been no terror attacks since 9/11 in the states, foremost among them being that they had the first one. The demographic profile of the Muslim community in the US is also very different. US Muslims are generally wealthier and better educated than the population at large. The pool of alienation and resentment which provides the political base from which bombers might emerge - the bombers themselves in Europe have been well-healed but the context is one of greater political resistance - is less pronounced here.

Indeed, according to a Pew survey that portion of the Muslim population here most likely to sympathise with violent acts are not from immigrant communities but African American converts. I think a terrorist outrage - God forbid - would increase pressure on Bush to pull out the troops. Most Americans I know disagree. They have logic on their side - acts of terrorism generally produce the kind of fear that prompts reactionary responses. But I think Americans are able to draw the conclusion that the war has made them more vulnerable and the war isn't working. I hope we never find out.