I have a largely observed rule on this blog that I don't get into the rights and wrongs of the 2003 Iraq invasion, as I think that - for someone like me to do so so - it is counterproductive.
But I thought Peter Wilby's argument yesterday was a very odd one. Yes - of course WWII was largely a continuation of the 'great powers' struggle that had dominated Europe since before Westphalia, with the new complication of the emerging United States as a dominant actor in the European stage. And there is the limit of my willingness to say anything authoritative on the wider historical context.
But the one lesson of WWII that surely unites almost everybody was that the rearmament limitations and the curtailment of Germany's expansionist ambitions that were imposed at Versailles should not have allowed to become a matter for pragmatism or flexibility.
That the international community as it was composed at the time - the League of Nations - needed to be able to assert itself effectively. It failed to do so and the result was a catastrophe.
In the run-up to 2003, Iraq was able to repeatedly frustrate attempts at weapons inspections - a demand that the UN was making unequivocally. Close observers of Saddam regularly reported that he believed that liberal democracies weren't capable of asserting themselves in this way.
I understand (and largely agreed at the time with) the argument that "...invading Iraq is a mistake because it probably won't be the success you think it will." It's a view that I held - and hold - with little enthusiasm.
But the experience of the WWII provided a justification for over-reaction in the face of suspicions - not inaction. It weakens - not strengthens - Wilby's anti-war position.