Combining civil and interstate wars

Quantitative studies of conflict analyze either civil or interstate war. While there may be observable differences between civil and interstate wars, theories of conflict focus on phenomena-such as information asymmetries, commitment problems, and issue divisibility-that should explain both conflicts within and between states. In analyses of conflict onset, duration, and outcome combining civil and interstate wars, we find most variables have similar effects on both types of war. We thus question whether there is any justification for separate study of war types.