Preferring the Peace

Via Logan, this Brad Plumer post:

At any rate, I can't see any real reasons why democracies wouldn't go to war with each other. Presumably I've missed something. But if not, that means the question of why, historically, democracies haven't bloodied each other up is mostly due to the fact that democracies are a recent phenomenon, the bipolar structure of the Cold War made everything weird, and the ironclad law's just an aberration.

Weird. I always that the answer was that people, when not inflamed by propaganda, as they tend not to be in democratic nations with a free press, don't like war. It's expensive and nice boys get killed. So leaders of democratic nations, who don't like getting kicked out of office, generally avoid war. Is it really more complicated than that? Justin?