International Law Studies


So far, outer space has merely become involved in terrestrial armed conflicts as part of the supportive infrastructure for military activities. Unfortunately, the risk that this changes is considerably growing, and it can no longer be excluded that (armed) force will become used in outer space, either directed towards Earth or within outer space itself.

This raises serious issues in the legal context, where space law so far has been premised on the hope that armed conflicts in outer space could be avoided whereas the law of armed conflict was not required so far to deal with the use of force in outer space. For the same reason, there is hardly any relevant State practice that could provide guidance here. While both legal regimes can loosely claim to constitute leges speciales as compared to the lex generalis of general public international law, and hence are doctrinally superior to the latter, this does not solve the issue of hierarchy in application as between those two leges speciales.

The current article presents a comprehensive effort to provide legal tools to determine where the law of outer space would overrule any incompatible law of armed conflict rules and vice versa, principally by constructing a matrix of prioritization. While too many different activities, events, scenarios, and developments could be envisaged for such a matrix to come up with easy and comprehensive answers, it nevertheless purports to provide initial guidance on how to address each particular possible activity, event, scenario, or development.