Why countries fight

From Myth of the Modern Religious War by John A. Tures. Testing the hypothesis that religion is a major source of international martial conflict.

To establish a baseline for comparing religious conflicts with other reasons why countries fight, we gathered information on three additional issues where Holsti collects data: real estate (territorial disputes), riches (battles over resources), and regimes (where one country attempts to replace another country’s government with one it prefers). Like the religion analysis, this involved bundling several of Holsti’s issues under a broader category for each issue of conflict, since many if not most wars have multiple issues. The results are listed below:

As you can see, in no time period since the Peace of Westphalia did religious wars ever constitute the dominant issue for why countries fight. In no case did religion ever consist of more than half the number of the next-lowest category of conflict.