Post-Chilcot, the anti-war left is as self-confident as ever.
It's not only the Chilcot Report itself. They also feel vindicated by horrific events across the Middle East.
They shouldn't feel so smug. In reality, they ignominiously failed to stop the wars in Afghanistan and Iraq - or the later bombings of Libya and Syria. If they are honest with themselves, they might realise why. However strong its merits, the non-interventionist case is overwhelmingly made by the wrong people in the wrong way. No wonder it keeps failing.
Iraq is the clearest example. Just about everyone now acknowledges the disaster the invasion soon became. But what is striking, looking back at the public debate prior to the invasion, is how poorly the key anti-war arguments addressed the disaster the Iraq invasion became.
Those who opposed the war from the beginning were of all politics. They included Conservative MPs, international relations academics, and pundits from left, right and centre. But in public debate it was overwhelmingly led by the left and the far-left.
Securing democratic liberal values in Iraq through military invasion was always unlikely to work. But leading anti-war voices (with very few exceptions) preferred to argue against this democratic vision not because it was implausible but because it was somehow undesirable.
Many opted for a profoundly unpersuasive relativism. The anti-war left was unwilling to make an argument about the actual capacity for democracy to triumph any time soon in the most illiberal parts of the world. So they instead argued that advancing liberal democracy was about advancing "Western values" that didn't particularly deserve to trumph. This extreme relativism was always likely to alienate the more level-headed, who may have agreed that Western values are difficult to export militarily, but also knew instinctively how much better Western values were than Saddam's.
Likewise, they could have acknowledged nationalism as a near-universal phenomenon, as a few realist academics did. They could have predicted that the one thing that would unite Iraqi Sunni and Iraqi Shia was the idea of defeating British and American troops on their soil. Perhaps because nationalism is so alien to the left, they ignored it and its consequences.
Similarly, they couldn't help but harness a deeply anti-American and often anti-Western mood. Looking back, the war was a costly and bloody humiliation for the West. If you wish the UK (and America) well, it is unlikely you would recommend more Iraqs. But back in 2002/2003, the anti-war movement made little of these self-interested reasons for Western countries to stay out of Iraq. The more paranoid implied a direct zero-sum narrative in which - far from losing so many lives and so many billions - the West would gain territory, influence and resources at the expense of the Arab world.
The left-wingers who led the anti-war movement could have built a much broader coalition based on the West's own self-interest and cynicism about the chances of democracy taking off in that part of the world. Instead they talked to themselves and rode minority interests like cultural relativism and anti-Americanism.
Above all, they obsessed over a certain understanding of international law. Even those who passionately believe that whether a country goes to war should be taken out of the hands of people we elect should be able to see how unappealing such explicitly undemocratic, elitist and process-based arguments usually are. Who really backed the war until they discovered that the UN Security Council wouldn't agree a second resolution? But international 'legitimacy' and the approval of the UN Security Council were given infinitely more airtime than than the merits or salience of the arguments deserved - perhaps alienating many who were on the fence about Iraq but value democracy.
The tragedy is that the UK (and US) could have benefited greatly if a considered, well-argued anti-interventionist case had been made. Even if it had failed to stop the invasion, it could have dramatically cut short many of the horrors of the post-war occupation.
We certainly need well-argued anti-interventionist arguments in the future - to stop more Iraqs before they start. We cannot leave this to the anti-war left.
Peter Cuthbertson runs the Centre for Crime Prevention, a non-profit aimed at reducing offending and reoffending. In 2015, he was the Conservative Parliamentary Candidate for his home town of Darlington.