If we're talking about national security problems, maybe it's the Secretary of State, maybe it's the Secretary of Defense, the Director of National Intelligence, maybe the ambassador to the United Nations, or somebody else who they think is going to know more about the particular problem.
安全保障問題に詳しいのは 国務長官 国防長官 国家情報長官 国連大使 あるいは他の担当官かもしれません