§ Lord Kennetasked Her Majesty's Government:
Whether they consider the placing of "Kinetic Kill Vehicles" in space to be in accordance with international law (either conventional or customary) and if so on which sources and authorities they base this view.
§ Baroness YoungUnder international law states have the inherent right of self-defence and may deploy weapons for that purpose. The 1967 Outer Space Treaty prohibits the stationing in outer space of nuclear weapons or other weapons of mass destruction but not the stationing of weapons as such. Whether the "Kinetic Kill Vehicle" should be regarded as a weapon of mass destruction would depend upon its characteristics.
The above may be subject to specific bilateral treaties, but these would not raise questions of general international law.