El Gato, what is the difference between an American citizen and an American national?
http://www4.law.cornell.edu/uscode/8/1101.html
Sec. 1101. - Definitions
(a) (22) The term ''national of the United States'' means
(A) a citizen of the United States, or
(B) a person who, though not a citizen of the United States, owes permanent [but not necessarily exclusive] allegiance to the United States.