Revelations that a North Korean missile fired by Russia in Ukraine contained a large number of components linked to U.S.-based companies underline the difficulty of enforcing sanctions against Pyongyang, but could help uncover illicit procurement networks, experts say. Conflict Armament Research (CAR), a UK-based organization that tracks the origins of weapons used in conflicts, examined the remnants of a North Korean ballistic missile used by Russia against Ukrainian forces in Kharkiv on Jan. 2