The Laws of War and Public Support for Foreign Combatants

Are publics in great power democracies more likely to approve of foreign armed combatants that comply with international humanitarian law (IHL)? There is a wealth of evidence that armed combatants with an incentive to seek the support of outside compliance constituencies are more likely to adhere to IHL. Yet a key mechanism underlying these claims—that people in great power democracies are more likely to support armed combatants that comply with IHL—has not been directly tested. We address this question using a series of experiments embedded in nationally representative surveys conducted in three democracies that have frequently been involved in foreign interventions: France, the United Kingdom, and the United States. We find that belligerents—both governments and rebels—that comply with the laws of war are significantly more likely to garner support from publics in likely intervening countries compared to those who do not comply. In all three countries, compliance with international law caused greater approval of armed combatants as well as greater support for economic or military intervention (although support for military intervention remained relatively low in the treatment groups). This lends support to arguments that, to the extent combatants seek support from outside audiences, this can serve as a mechanism by which international law constrains armed combat.