Extraterritorial operation

An extraterritorial operation in international law is a law enforcement or military operation that takes place outside the territory or jurisdiction of the state whose forces are conducting the operation, generally within the territory of another sovereign state. Under international law, these activities are generally highly restricted, and it is considered a violation of a state's sovereignty if any other state engages in law enforcement or military operations within another state without gaining that state's consent:

The first and foremost restriction imposed by international law on a State is that—failing the existence of a permissive rule to the contrary—it may not exercise its power in any form in the territory of another State.

— Permanent Court of International Justice, 1923