These guys are soldiers out of uniform, clearly hostile to US interests and humanity itself.
National Self Defense: The act of defending the U.S.; U.S. forces; and in certain circumstances, U.S. citizens and their property, U.S. commercial assets, other designated non-U.S. forces, foreign nationals and their property, from a hostile act or hostile intent. As a subset of national self-defense, the act of defending other designated non-U.S. citizens, forces, property, and interests is referred to as collective self-defense. Authority to exercise national self-defense rests with the NCA, but may be delegated under specified circumstances; however, only the NCA may authorize the exercise of collective self-defense.
The SROE distinguish between the right and obligation of self-defense—which is not limited—and use of force for the accomplishment of an assigned mission. Authority to use force in mission accomplishment may be limited in light of political, military or legal concerns, but such limitations have no impact on the commander's right and obligation of self-defense.
Once a threat has been declared a hostile force, United States units and individual soldiers may engage without observing a hostile act or demonstration of hostile intent. The basis for engagement becomes status rather than conduct. The authority to declare a force hostile is given only to particular individuals in special circumstances.
Appendix A to Enclosure A of the SROE contains guidance on this authority.