Kawakita v. United States, 343 U.S. 717 (1952), is a United States Supreme Court case in which the Court ruled that a dual U.S./Japanese citizen could be convicted of treason against the United States for acts performed in Japan during World War II. Tomoya Kawakita, born in California to Japanese parents, was in Japan when the war broke out and stayed in Japan until the war was over. After returning to the United States, he was arrested and charged with treason for having abused American prisoners of war. Kawakita claimed he could not be found guilty of treason since he had lost his U.S. citizenship while in Japan, but this argument was rejected by the courts, which ruled that he had in fact retained his U.S. citizenship during the war. Originally sentenced to death, Kawakita's sentence was commuted to life imprisonment, and he was eventually released from prison, deported to Japan, and barred from ever returning to the United States.

United States nationality law details the conditions in which a person holds United States nationality. In the United States, nationality is typically obtained through provisions in the U.S. Constitution, various laws, and international agreements. Citizenship is established as a right under the Constitution, not as a privilege, for those born in the United States under its jurisdiction and those who have been "naturalized". While domestic documents often use the words citizenship and nationality interchangeably, nationality is a broader term that refers to national identity and formal membership in a nation, while citizen is reserved to nationals who have the recognized status of citizenship.