Republican liberalism

Republican liberalism is an international relations theory which claims that liberal democracies (almost) never fight each other, and in that sense are more peaceful. However, the theory does not propose that democracies are more peaceful than non-democracies, as many democracies are engaged in wars with non-democracies. The theory holds that the reason for this intra-democratic peace is rooted in the regime type of these countries (democracy) and the existence of similar domestic political cultures, common moral values, economic cooperation and interdependence.