The existing legal framework has both gaps and areas of relevance for contemporary challenges and threats. The Outer Space Treaty (OST) contains an arms control provision through Article IV which prohibits the placement of weapons of mass destruction in orbit, installation on celestial bodies or stationing in outer space. The Partial Test Ban Treaty prohibits nuclear explosions in outer space. Beyond these two treaties, military activities in space are constrained by the OST’s provision on avoiding harmful interference and the need for actions to be guided by due regard to the interests of other States Parties (Article IX). Additional ‘soft law’ guidelines include the Space Debris Mitigation Guidelines, and a relevant query was raised regarding the relationship between debris and harmful interference.
Participants further discussed the relevance of international law such as the UN Charter and prohibitions on the use of force, acknowledging that fundamental international law concepts have yet to be clearly applied to space. This includes the right to self-defence under the UN Charter, as well as international humanitarian law principles such as distinction and proportionality during armed conflict, especially considering how critical civilian infrastructure and humanitarian services have become increasingly dependent on space. The application of principles found in international law such as due regard and common heritage require clarification as well. United Nations General Assembly (UNGA) resolution 3314’s definition of aggression was raised for its potential relevance in aiding common understanding.
Because space is far from a ‘legal wild west,’ numerous ideas were offered on how to better make use of the existing legal framework. There were calls for the universalization and implementation of space treaties as well as detailed considerations on operationalizing existing provisions. For example, what would consultations under Article IV of the OST involve? Could it have been invoked in past incidents where it was not, and might scenario exercises aid in figuring out instances for future applicability? Such inquiries could reveal areas which require supplementing with new legally binding or non-legally binding measures. The possibility of an optional protocol for the OST was raised as well.
A debate ensued regarding aspects of possible future legally binding measures on PAROS. The definitional question of what is a space weapon persists. There was a suggestion that it may be possible to define weapons in an operational method, with the Chemical Weapons Convention held as an example where a chemical weapon is a “chemical substance… used as a weapon.” It was also suggested that some space objects may be easier to define as a weapon, even if other types of space objects (those of a dual use/dual-purpose nature) have proved to be trickier. The discussion noted that some disarmament treaties contain no definitions such as the Treaty on the Non-Proliferation of Nuclear Weapons.
The issue of (dis)trust featured prominently. While there were disagreements over where and how trust factors into PAROS considerations (e.g. is trust required to launch a legally binding process, or/and could it be built up through non-legally binding measures) there was general agreement that trust could and should be improved on. To that end, the Dialogue’s session on TCBMs proved to be informative.