In the contemporary period, many military forces rely heavily on space-based assets to conduct operations across a wide spectrum of contexts. Such reliance necessarily exposes a correlative vulnerability that such assets may be degraded or destroyed, especially in a time of armed conflict. However, the legal framework that governs military action in space during a time of armed conflict is not well explored. This article examines the interaction between International Humanitarian Law (IHL) and the Outer Space legal regime. Harmonization of legal regimes is a goal of any reconciliation project, although such harmonization may not always be readily possible. In such circumstances legal interpretative mechanisms that seek either a vertical hierarchy (jus cogens) or a horizontal priority (lex specialis) may apply, but their utility is often elusive in particular situations. Hence, in those situations identification of relevant state practice can provide a more reliable guide as to treaty context and thus better identify respective objective preferences. Though even here there may not be sufficient state practice, or it might be too diffuse. Thus, when all “normal” legal tools fail to render a satisfactory outcome, this article concludes that a stark policy choice will need to be made between what aspects of which particular treaty regime will apply. It offers a set of principles that might be invoked as a solution. Such an approach is advanced as means of resolving differences by assimilating common value commitments contained within both the IHL and the Outer Space treaty regimes to provide a viable means of harmonization.