University of Miami Inter-American Law Review


The military actions of an International Coalition and the role of its non-military contributing member States is yet another fundamental example of international practice concerning conflation between jus ad bellum and jus in bello. Although International Law proscribes the use of force in international relations, membership in an International Coalition engaged in military operations does not come without a cost. Non-military contributing member States may be regarded as co-belligerents or neutral States violating the laws of neutrality. This article argues that mere membership in a coalition does not amount to co-belligerency. Nevertheless, it claims that membership could entail a violation of the laws of neutrality, authorizing the use of countermeasures or lawful reprisals. The article analyzes the practice of Panama as part of the allies in World War II, the coalition of willing in Iraq (2003), and the coalition to counter ISIL in Iraq and Syria (2015). In doing so, it considers the applicable laws and possible conflicts between jus ad bellum and jus in bello.