Why a President Cannot Authorize the Military to Violate (Most of) the Law of War

Abstract

Waterboarding and “much worse,” torture, and “tak[ing] out” the family members of terrorists: President Trump endorsed these measures while campaigning for office. After his inauguration, Trump confirmed his view of the effectiveness of torture and has not rejected other measures forbidden by international law. This article therefore examines whether a president has the power to order or authorize the military to violate international humanitarian law, known as the “law of war.” Rather than assess whether international or federal law generally constrains a president as commander-in-chief, however, its focus is the extent to which Congress requires the U.S. military to comply with the law of war in its disciplinary code, the Uniform Code of Military Justice (UCMJ). It clarifies the extent to which Article 18 of the UCMJ, which vests general courts-martial with jurisdiction over offenders and offenses triable by military tribunal and to impose punishments “permitted” by the law of war, requires law of war compliance. It explains how Article 18 empowers courts-martial to try and punish not only war crimes defined by international law but also other law of war violations that entail a criminal offense under the UCMJ. Put differently, the article clarifies why reasonable compliance with the law of war is necessary to justify common war measures that are otherwise crimes punishable under the UCMJ, such as murder, maiming, assault, and arson. The article then explains why this domestic execution of the law of war limits a president’s authority as Commander-in-Chief: a president does not possess constitutional power to override congressional regulation of the military. So long as Article 18 remains unchanged, no president may order or authorize war crimes or other law of war violations that entail a crime under the UCMJ.