22 U.S.C. § 449
American republics
This subchapter (except section 452 of this title) shall not apply to any American republic engaged in war against a non-American state or states, provided the American republic is not cooperating with a non-American state or states in such war.
( Nov. 4, 1939, ch. 2, § 9 , 54 Stat. 8 .)