'Enemy aliens' usually refers to people such as prisoners of war that are from the opposing country in a war. It can also be used in a political sense.
"In WWII, Japanese enemy aliens were kept in containment camps mostly in the interior of British Columbia."
"During the Cold War, propaganda was used to prevent and/or keep down political enemy aliens.
"During the Cold War, propaganda was used to prevent and/or keep down political enemy aliens.
by Nicholas A. June 5, 2007