The democratic peace theory—the idea that democracies do not fight other democracies—is well known. What is less well known is that democracies win the wars they fight.52 Indeed, since 1815, democracies have won over 76 percent of their wars. Compare this to the much lower success rate of autocracies, which have been victorious in only 47 percent of cases. Statistical tests reveal that regime type is an important determinant of victory in war even after controlling for other factors that might matter, such as military power, terrain, strategy, allies, and distance.
