The research and development, testing, production, storage, and deployment of antisatellite weapons (ASATs) is limited directly by the law of space arms control and indirectly by the law of environmental protection. The former only prohibits the testing and deployment of ASATs in a partial manner, with conventional space-based ASATs and ground-based ASATs unaddressed. The latter may constrain the right to test and use ASATs, by limiting their exterior impact on the environment and/or their potential interference with others’ activities. While the law of environmental protection is complementary to the law of space arms control in protecting the space environment from damage caused by military activities, to address the core issue of space security lies in the strengthening of space arms control itself.