War & peaceNo “democratic peace”: Democracies are as likely to fight each other as other types of government

Published 4 September 2015

Democratic peace is the widely held theory that democracies are less likely to go to war against each other than countries with other types of government. Using a new technique to analyze fifty-two years of international conflict, researchers suggest that there may be no such thing as a “democratic peace.” In the new study, researchers found that economic trade relationships and participation in international governmental organizations play a strong role in keeping the peace among countries. But democracy? Not so much. In addition, a model developed with this new technique was found to predict international conflict five and even ten years in the future better than any existing model.

Using a new technique to analyze fifty-two years of international conflict, researchers suggest that there may be no such thing as a “democratic peace.”

In addition, a model developed with this new technique was found to predict international conflict five and even ten years in the future better than any existing model.

Democratic peace is the widely held theory that democracies are less likely to go to war against each other than countries with other types of government. In the new study, researchers found that economic trade relationships and participation in international governmental organizations play a strong role in keeping the peace among countries.

But democracy? Not so much.

“That’s a startling finding because the value of joint democracy in preventing war is what we thought was the closest thing to a law in international politics,” said Skyler Cranmer, lead author of the study and The Carter Phillips and Sue Henry Associate Professor of Political Science at the Ohio State University.

“There’s been empirical research supporting this theory for the past 50 years. Even U.S. presidents have touted the value of a democratic peace, but it doesn’t seem to hold up, at least the way we looked at it.”

The study appears this week in the Proceedings of the National Academy of Sciences. Cranmer’s co-authors are Elizabeth Menninga, assistant professor of political science at the University of Iowa and recent Ph.D. graduate in political science at the University of North Carolina at Chapel Hill; and Peter Mucha, professor of mathematics in the College of Arts and Sciences at UNC-Chapel Hill.

An OSU release notes that along with casting doubt on democratic peace theory, the study also developed a new way to predict levels of international conflict that is more accurate than any previous model. The researchers used a new technique to examine all violent conflicts between countries during the period of 1948 to 2000. The result was a model of international conflict that was 47 percent better than the standard model at predicting the level of worldwide conflict five and even ten years into the future.

“The Department of Defense needs to know at least that far in advance what the world situation is going to be like, because it can’t react in a year to changes in levels of conflict due to bureaucratic inertia and its longer funding cycle,” Cranmer said.