One of the worst effects of the Iraq invasion has been the loss of confidence in the virtue, for Britain and America, of invading foreign countries for moral reasons and the resurrection of the doctrines of realism, isolationism, and that matters occuring in countries "far away...about which we know little" are nothing to do with us.
We had thought we had put this old-fashioned, outdated idea behind us, after it was totally discredited by resulting in the hideous mass slaughter of Rwanda and the massacre at Srebrenica. Instead, under Blair we had the doctrine of liberal interventionism, spectacularly successful in Sierra Leone, Kosovo and Serbia. But realism is a many-headed hydra, hard to kill, and with the slightest setback - in Iraq, for example - it has returned with a vengance. So it is necessary to explain, once again, why morally-driven interventionism is justified.
The reality is this: the world contains some very bad people and some people that do very bad things if put into the right situation. They sacrifice their children, burn their widows, mutilate their daughters, persecute their political enemies, murder their religious opponents, oppress the good, enslave those of other races, ruin their economies, corrupt the noble, impoverish the poor, deny knowledge to the ignorant, and empower the wicked.
And whilst many of you are appear to believe that a country that does these things is no worse than a country in which MPs claim £4.20 too much in expenses, I and those that think as I do will be trying to stop them. Because (a) I am under a moral obligation to try to save the weak and oppressed, to protect the innocent, to educate the ignorant, for I am strong and well-allied and morally enlightened; and (b) I actually care about trying to stop wickedness and want to do so rather than tell myself stories about how it would be better if I did nothing and I am willing to take as a consequence that I shall sometimes make mistakes and make things worse rather than better. For to act is to risk, but to sit and excuse inaction is to leave the world to the wicked.
Many people say things along the lines of: Britain and America are not morally perfect. What business is it of ours to impose our ways on others? And in commenting on our imperfections they are of course right. But the truth is that though we in America and Britain are far from perfect - I offer many criticisms of our society in the hope that we might improve - we are enormously better than those societies (and there are many) that do the things I described above. And it is foolish self-hatred to deny this, empty and self-indulgent. And the sad thing is that we have many empty, self-indulgent, self-hating people in our society in this particular area - people that are otherwise intelligent and charming and morally upright, but have become enthralled by the false prophecies of political relativism. Realism and its cousin political relativism are the doctrines of the many. Mercifully, mine has almost always been the doctrine of the elite of Britain - and it is precisely because of the doctrine of the elites of Britain and her daughter America that so much of the world is liberal and peaceful and prosperous instead of enthralled by dictators armed with the merciless machines of modern science.
Remember what we are discussing here. We aren't talking about other societies that just prefer different kinds of cheese. I'm not proposing to invade them just because I think they design their buildings in an unimaginative way or because they prefer celtic football to Rugby. I don't offer as casus belli that they have naff pop music or prefer Wimpy to MacDonalds. People all over the world are lazy, indeed slothful (I know that I am) and sloth is a much more destructive sin than most people recognise. Many in our society are too lax in their use of pornography - with consequences far beyond their imagining. We impinge upon the liberty of ethnic minorities with our stop and search. We undermine religious freedom with our anti-hate laws.
These are important matters. But, at the risk of stating the obvious, there is a difference between watching too much porn and slaughtering a million of our neighbours or chopping off the arms of all the children in the next-door village. It may not be the difference that one is wrong and the other is not - they are both sinful. But there is a difference nonetheless.
I'm talking about situations like Rwanda where intervention could have saved millions of people's lives, but we were too obsessed by our doctrines of sovereignty to intervene, or the horrors of the Balkans, or the mass amputations of Sierra Leone. The places Britain invades have been places of appalling, appalling violence and oppression.
The truth is that the key issue is not when we have the moral entitlement to invade. We are morally entitled to invade - what? - anything up to half the world at any one point in time. The issue is when we are morally obliged to do so, and what our priorities should be in such wars - we have only finite resources and cannot spend our whole time invading places, so we must choose.
I had thought that Iraq was a priority because of its record in the 1990s. I was wrong. That's how it goes. I am not shaken by that in terms of the necessity and duty of projecting our values with military power. I am shaken concerning the appalling failure of the intelligence process over a decade. But that's another story.
Regardless of that, future historians will look back and judge that the Iraq invasion, which was heavily criticised at the time, was in the end vindicated by bringing democracy and stability to Iraq, and that Iraq subsequently provided a model for other Arab states to follow, leading over time to the spread of liberal democracy across much of the Arab world. Issues of 45 minutes will not feature large in their discussions. But what might feature is this: Britain, having been at the forefront of the invasion itself, then totally blew it when it came to the management of Basra, then panicked just at the turning point of the conflict with the surge, and fled instead of of sticking it out, becoming the rats that fled the floating ship. We have much to reflect upon.
But the lesson we must not learn is that the realists wish to teach us. Please, Mr Cameron, don't take that path!