act-of-state doctrine.Int’l law. The principle that no nation can judge the legality of a foreign
country’s sovereign acts within its own territory. • As originally formulated by the U.S. Supreme
Court in 1897, the doctrine provides that “the courts of one country will not sit in judgment on the
acts of the government of another done within its own territory.” Underhill v. Hernandez, 168 U.S.
250, 252, 18 S.Ct. 83, 84 (1897). The Supreme Court later declared that though the act-of-state
doctrine is compelled by neither international law nor the Constitution, it has “institutional
underpinnings.” Banco Nacional de Cuba v. Sabbatino, 376 U.S. 398, 423, 84 S.Ct. 923, 937
(1964). [Cases: International Law 10.9. C.J.S. International Law § 34.] [Blacks Law 8th]