18 U.S.C. § 756

Whoever, within the jurisdiction of the United States, aids or entices any person belonging to the armed forces of a belligerent nation or faction who is interned in the United States in accordance with the law of nations, to escape or attempt to escape from the jurisdiction of the United States or from the limits of internment prescribed, shall be fined under this title or imprisoned not more than five years, or both.