Keep pulling the thread on Donald Trump.
The lawsuit Regan v. King argued that native-born Japanese Americans should be stripped of their citizenship due to a theory of dual allegiance, as Japan's citizenship laws automatically treated them as citizens of the Empire of Japan during World War II.
Supreme Court Justice Samuel Alito raised a national security concern that current U.S. birthright citizenship rules could grant citizenship to a child of an Iranian father, who would simultaneously hold Iranian citizenship and a military allegiance to Iran.
United States law includes provisions for stripping citizenship from an American who serves in a foreign military that is acting against the United States.