Lecture summary: In 2015, the United States military dropped a bomb on a hospital in Afghanistan run by Médecins Sans Frontières, killing forty-two staff and patients. Testifying afterwards before a Senate Committee, General John F. Campbell explained that “[t]he hospital was mistakenly struck.” In 2019, while providing air support to partner forces under attack by ISIS, the U.S. military killed dozens of women and children. Central Command concluded that any civilian deaths “were accidental.” In August 2021, during a rushed withdrawal from Afghanistan, the U.S. military executed a drone strike in Kabul that killed ten civilians, including an aid worker for a U.S. charity and seven children in his family. The Pentagon later admitted it was a “tragic mistake.” In these cases and others like them, no one set out to kill the civilians who died. Such events are usually chalked up as sad but inevitable consequences of war - as regrettable “mistakes.”

In this lecture, based on a forthcoming co-authored article, Professor Oona Hathaway will examine the law on “mistakes” in war. She will consider whether and when the law holds individuals and states responsible for “mistakes.” To see how the law works, or fails to work, in practice, she will examine the US military’s own assessments of civilian casualties. She will show that “mistakes” are far more common than generally acknowledged. Some errors are, moreover, the predictable - and avoidable - result of a system that does too little to learn from its mistakes. She will focus her remarks on the United States, both because of its global military operations and because of the power of its example to shape global practices. The United States is far from alone, however. Thus, lessons learned from its failures can be instructive for other states as well.