Democracies are describes as having three virtues: Freedom, Prosperity and Peace. Democracies have a fourth virtue that most people remain silent about. It is not polite to say it outloud.

Democracies win wars. They are very belligerent states too.

Largely underappreciated by scholars and political observers has been a fourth virtue of democracy: democracies win wars. Since 1815, democracies have won more than three quarters of the wars in which they have participated.

This goes against a popular belief. Democracies have peaceful internal politics, where people negotiate and compromise. The virtues of freedom and commerce do not seem at first glance to contribute to the discipline and brutality that is needed in war. Yet it does. Free men make the best warriors.

Soldiers in a democracy display superior leadership, individualism and initiative in combat. These are the decisive factors for victories.

I would argue that this has always been the case. The best soldiers were generally drawn from the middle class. In ancient times, like Greece or Republican Rome, the soldiers paid for their own armor. The middle class also had the greatest incentive to fight to defend their interests, unlike the poor, ill equipped lower class.

The authors offer several hypotheses and proceed to shoot down most. The surviving hypothesis is that skill of the common soldiers and officers in democracies exceed the skill of soldiers and officers in autocracies. It is the body of citizen-soldiers, not great generals or politicians, who succeed.

This is suggestive of something beyond their research. Democracies create a more talented body of citizens than autocracies. This is true for the economy and the military. Democracies allow criticism and reevaluations of ideas and strategies. The men are better trained, more rational, and better equipped. The culture of democracy encourages decentralized command, initiative, and accountability. When a state goes to war, the tip of the spear is a reflection of the total strength of the culture. And democracies win.

War is a complex adaptive system. It consists of non-linear interacting parts that self-organize into order. Battles are decentralized affairs as there is no central direction.

This anarchic environment places the democratic soldier at an advantage. Democracies win for the same reason they dominate the marketplace. The nations of shopkeepers, the UK and US, have been the military and economic hegemonies of the past two centuries, possibly for the same reason.

Autocrats prefer yesmen delivering pleasing falsehoods. Dictatorships rely on inefficient command and control economies. They bribe off their small group of supporters and often divert resources for corruption. Over the long term, this creates corrupt, poorly trained and led armies. Soldiers in autocracies are often conscripts who have no vested stake in their government. Slave soldiers are easy to beat.

There is a selection bias at work. Democracies have not fought another democracy in modern times. They wage war against autocracies which are often weaker states. As time goes on, democratic states grow more and more powerful economically and culturally.

Democracies do have a weakness: Time. As the time at war grows, democracies become more impatient and more willing to cede victory (even if they can win). This gives autocracies the chance to outwait a democracy in order to win. Unlike Democrats, Autocrats are not held accountable for waging prolonged wars.

The authors address alternative explanations.

Here are two hypotheses that are commonly held myths.
Myth #1: Democracies create alliances and and defend one another in a noble fraternity.

No they don’t. Democracies are not statistically more likely to wage war to defend another democracy than any other state. Remember how many times France was overrun and the Americans remained neutral?

Myth #2: The Materialschlacht. Democracies superior economic management creates an arsenal of democracy that wins the war through material attrition.

Not exactly. While economics are important, most wars are determined before a true Materialschlacht takes place. Autocracies can create an industrial base to challenge a democracy for the duration of a war.

The real benefit of the economic superiority is with the soldier, not his equipment.