Internee of belligerent nation
Official text prohibited actmental stateif conditionpenaltylegal term
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 or imprisoned not more than five years, or both.
History: (June 25, 1948, ch. 645, 62 Stat. 735 (PDF, 39 MB); Pub. L. 103–322, title XXXIII, §330016(1)(H), Sept. 13, 1994, 108 Stat. 2147 (PDF, 52 MB); Pub. L. 104–132, title VII, §705(a)(3), Apr. 24, 1996, 110 Stat. 1295.)
Simplified explanation
It is a federal crime, within U.S. jurisdiction, to help or lure a member of a foreign country's armed forces who is being held (interned) in the U.S. during a war to escape. This covers escaping the country or leaving the area where they must stay.