Yes, even Tony ‘Pants on Fire’ Blair was invoking the ‘truth’ of this statement recently when he was interviewed by John Stewart on American television (the last refuge of a scoundrel). But is it true?
Here is an online analysis of the topic: ‘Democracies Do Not Make War on One Another….or Do They?‘, in which Matthew White gives ‘traditional list of wars which may or may not have been fought between democracies’. 23 wars, in fact (become obessed with numerology, miss 7 turns). Also White gives us the mathematical probability of two democracies going to war, given the number of democracies on Earth (bet you hadn’t thought of that, eh?)
