This essay discusses the threshold of application of international humanitarian law (IHL) in both international (IAC) and non-international armed conflicts (NIAC). In relation to IAC it questions whether the International Committee of the Red Cross (ICRC) “first shot” approach is the most appropriate, since it opens the way for the intensification of conflicts beyond what is necessary in relation to relatively minor armed incidents and argues that the humanitarian protection clauses of IHL should be separated from the rules governing hostilities and makes a case for the application of ad bellum considerations of necessity and proportionality to act as a parallel set of constraints on the targeting of persons and objects alongside IHL rules on targeting. The essay then goes on to discuss the consequences of lowering the threshold of armed conflict in NIAC while exponentially increasing the number of applicable rules to armed groups, regardless of their degree of ability to comply with many of those rules. It advocates a basic set of rules relating to both the conduct of hostilities and treatment of persons to all NIACs and a progressive increase in the number of rules as the conflict intensifies and the armed group takes on more of the characteristics of a State. Finally, the essay discusses the ICRC’s “support based approach” (SBA) for determining when a multinational force or other entity becomes party to an ongoing armed conflict and advances arguments against the acceptance of the SBA as law or policy.