Kawakita v. United States
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.
343 U.S. 717 · No. 570 · 1951 term · Vinson Court
Decided Jun 2, 1952 · argued Apr 2, 1952
Criminal procedure · Statutory construction of criminal laws: war crimes
Majority opinion: William Douglas
The voteMajorityDissent
4–34 in the majority, 3 in dissent
3 dissents (6–3)
Affirmed. Kawakita lost.
What this ruling means
Affirmed: the Supreme Court upheld the decision of the U.S. Court of Appeals, Ninth Circuit, so it stands (sometimes with changes the Court made to it).
Kawakita was the petitioner, the side that asked the Supreme Court to review the case. “Lost” means the Court did not give that side the result it asked for.
From the Supreme Court Database. A justice who agreed with the result but not the reasoning counts in the majority.
Summary
The opening of the case’s Wikipedia article: what the case was about and what the Court held.
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 (including the Supreme Court), 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.
Kawakita is currently one of the last people to be convicted of treason in the United States. One other person, John David Provoo, was convicted of treason in 1952. However, Provoo's conviction was overturned on appeal. As such the distinction instead goes to Herbert John Burgman, who was convicted of treason in 1949.
Data notes
The text is Wikipedia’s (CC BY-SA 4.0), matched to the case by its citation, docket number or name and year, and is not checked against the opinion. The site keeps the article’s opening section, ending on its last full sentence. The one-sentence summary under the title is the Decisions list’s: Wikipedia’s own ruling sentence, or, tagged “AI-written”, one Claude wrote from this opening.
How the justices voted
Each justice who took part, placed by their Martin–Quinn ideology score for the 1951 term. Filled: the 4 in the majority. Hollow: the 3 in dissent. Colour is the party of the president who appointed them.
Majority(4)
William DouglasWrote the majority opinion
Robert JacksonJoined the majority
Stanley ReedJoined the majority
Sherman MintonJoined the majority
Dissent(3)
Frederick VinsonWrote a dissent
Hugo BlackJoined a dissent
Harold BurtonJoined a dissent
Did not take part: Felix Frankfurter, Tom Clark.
Data notes
Each justice’s vote and what they wrote are from the justice-centered file of the Supreme Court Database. “Wrote a concurrence” means the justice sided with the majority and wrote separately; a justice who dissented in part is counted on the side they took overall. A justice who wrote nothing is listed as joining their side.
Positions are each justice’s Martin–Quinn score for the case’s term, the same scores as the Ideology page: negative is more liberal, positive more conservative. A score sums up a justice’s votes across the whole term, so it says where they usually sit, not why they voted as they did here. The median line is the Court’s median justice that term.
The parties
Who brought the case to the Court, who answered it, and how it got there.
- Petitioner
- KawakitaPerson accused, indicted, or suspected of crime
- Respondent
- United StatesUnited States
- Reached the Court by
- Certiorari (the Court chose to hear it)
Data notes
The names are the two sides of the case’s title. The description under each is the Supreme Court Database’s category for that party, in its own wording. The petitioner is the side that asked the Supreme Court to review the decision below. “Why it was taken” appears only when the majority opinion says lower courts disagreed or were unsure about the question; reasons that would fit any case (“to resolve the question presented”, “an important question”) are left out.
The law at issue
The law the Court was asked to apply, and the kind of power it used to decide.
- Provision
- Immigration and Naturalization, Immigration, Nationality, or Illegal Immigration Reform and Immigrant Responsibility Acts, as amended
- Kind of law
- Federal Statute
- Decided by
- Statutory construction
Data notes
The Supreme Court Database codes the main constitutional provision, statute or court rule each case turned on, and the basis of the decision: judicial review of a federal or state law, interpreting a statute, supervising the lower courts, and so on. A case can rest on more than one. “Overruled” counts only where the majority opinion says so.
Timeline
What happened at the Court and how the case got there, newest first.
- Jun 2, 1952DecidedDecided · Decided 4–3: affirmed. Kawakita lost.
- Apr 2, 1952ArguedArgued · Oral argument before the Court.
- Not datedTaken upTaken up · The Supreme Court agreed to hear the case (certiorari).
- Not datedCourt belowCourt below · Decided by the U.S. Court of Appeals, Ninth Circuit: affirmed.
- Not datedBeganBegan · The case began in the California Southern U.S. District Court.
Data notes
From the Supreme Court Database: the court the case began in, the court whose decision the Supreme Court reviewed and what that court did, how the case came to the Court, and the dates of argument and decision. The database does not date the steps in the lower courts. Court names are the database’s.
Other decisions on the same issue
2 other argued cases since 1946 on statutory construction of criminal laws: war crimes, newest first.
- United States, Petitioner v. Anthony James Kebodeaux570 U.S. 387Jun 24, 2013 · 570 U.S. 387Criminal procedure7–27–2 band
- Mogall v. United States333 U.S. 424Mar 8, 1948 · 333 U.S. 424Criminal procedure9–0Unanimous band
Data notes
Every other orally argued case with a clear vote, from the 1946 term on, that the Supreme Court Database files under the same issue as this one. The database gives each case one issue from a list of about 270 (abortion, search and seizure of vehicles, the death penalty, and so on), whatever law it turned on.
Official record
Read the full opinion on Justia and Wikipedia. Case data from the Supreme Court Database, Version 2026 Release 01, through the 2025 term.