The debates over the applicability and interpretation of the Law of Armed Conflict (LOAC) are vital to unity of effort as well as clarity of rules in coalition operations. This paper has addressed the key sources of uncertainty underlying how LOAC is and should be applied in coalition operations, focusing first on understanding which legal frameworks apply in particular context of armed conflict. After addressing key current debates over the qualification of conflicts, the paper explores a number of contemporary contexts in which this question of applicability is most salient: intervention in failed state situations and transnational armed conflicts. The paper suggests that resolving this first uncertainty is critical to unity of effort in this increasingly common realm of operations. It then suggests that a number of ongoing questions in the arena of LOAC applicability and interpretation exist where conflicts may be bifurcated and in determining the end of armed conflict. The paper explores the common practice of imposing policy‐based LOAC requirements in coalition situations, and how such practices are relevant to detention policies, command responsibility in situations where multi‐national forces are acting in concert, debates over direct participation of civilians in armed conflict, and the involvement of civilian support personnel in contemporary conflicts.