This article analyses policing, ill-discipline, and crime in the Australian–American alliance during the Second World War. Though these topics have received considerable scholarly attention, previous studies have been narrowly focused both geographically and thematically. Providing a broad analysis of these subjects, this article places these issues within their wider political and legal context, and examines the nature of cooperation between Australian police (both military and civil) and their US allies. It also traces general patterns of ill-discipline and crime in Australia and its territory of Papua and mandate of New Guinea, highlighting policies that successfully limited inter-Allied violence.