This chapter addresses what to some has become a legal Gordian Knot - detention during armed conflict. Similarly to Alexander's approach of cutting the knot, this chapter takes a pragmatic approach to detention. This chapter begins by providing an overview of the traditional law of armed conflict applicable to detention during international armed conflict (IAC). Next it provides an overview of the law of armed conflict applicable to non-international armed conflicts (NIAC). From there the chapter explains several of the contemporary challenges to the traditional IAC model. The chapter concludes by proposing that the 1949 Geneva Conventions and the 1977 Additional Protocols, outmoded and seemingly inapplicable though they may be in some respects, offer the most thorough, humane, realistic and readily available option for determining how to treat and when to release non-state actors detained during a NIAC.