Last night we had dinner with friends in a hilltop restaurant in Provence. We sat on the terrace, looking down on the valley below, with the blue remembered hills of the Luberon in the distance. It was one of those beautiful Provencal evenings — warm and comforting, with that marvellous light that brought Van Gogh, Cezanne & Co to this part of the world. All around us were the murmurs of conversation from other diners. At a nearby table was a large party of Spanish cyclists who had just returned from climbing Mont Ventoux. It was wonderfully peaceful and convivial, made even better by the company and two nice Cote du Rhone wines.

And then I suddenly thought that on an evening just like this, 100 years ago, there would have been parties of comfortable French bourgeoisie sitting in just such a restaurant as this, enjoying a quiet evening together, with no idea of what was to come, no real appreciation of the horrors that European nations were about to unleash upon one another.

And then I thought: surely it couldn’t happen again. Could it?. See Article 5 of the treaty that set up NATO.