Jason says that democratic peace theory is one of the better explanations for the decline of large-scale conflict around the globe. I remain unconvinced – here’s why:
1) This ain’t the Theory of Gravity we’re talking about. Until recently, democracies were remarkably rare. The third and fourth waves of liberalization still qualify as recent events. To put it in scientific terms, I’d say that more tests are needed.
2) There are too many confounding variables to account for. Until now, most major democracies shared important cultural commonalities (here, I’m thinking mainly of the Anglosphere and Western Europe) that probably won’t exist at future flashpoints. Economic interdependence between the United States and Europe – a factor Mack identifies as significant in his opening entry for Cato Unbound – may have also payed a role in deterring conflict. Europe’s unique post-war experience is another variable to account for: After enduring two world wars, I suspect a strong aversion to open conflict would have developed absent democratic governance.
By way of comparison, consider the Congress of Vienna and the subsequent peace between the Great Powers in 19th century Europe. Metternich, the architect of the post-Napoleonic framework, was an arch-reactionary, and none of the major participants would have qualified as liberal democracies in the modern sense of the words. But peace prevailed across the continent for the better part of a century. Disastrous wars have a way of binding nations together, at least temporarily.
3) Outside pressure encourages solidarity and deters conflict among allies. Would our democratic peace have been nearly as potent if the major democracies were not bound by military and political alliances, first against Hitler and later against the Soviet Union? Even after the threat has lapsed, the mechanisms of cooperation – NATO, the EU, SEATO etc. – remain in place, providing a ready-made framework for consultation and conflict avoidance that won’t exist among newer democracies.
I’m not dismissing the idea that certain shared political norms make conflict between democratic countries unlikely. But if we’re taking bets, I’d put my money on the “mature, Western, economically-interdependent liberal democratic peace theory” over the plain old democratic peace theory any day.