## Facts

- Seven Japanese protesters, including Sakata, entered the U.S. Tachikawa Air Base area during protests against expansion of the base into nearby farmland.
- The protesters opposed land expropriation and eviction of local farmers connected to the proposed runway expansion.
- The defendants were arrested and charged under a special criminal statute imposing enhanced (felony-level) penalties for trespass on U.S. military bases, rather than ordinary trespass penalties.
- The defense argued the U.S.-Japan Security Treaty authorizing the stationing of U.S. forces in Japan violated Article 9 of the Japanese Constitution, which renounces war and forbids maintaining “war potential.”
- The Tokyo District Court acquitted the defendants, reasoning that the Security Treaty was unconstitutional under Article 9 and that the base-protection trespass statute, as implementing legislation, was therefore invalid.
- Prosecutors appealed, and the case proceeded to the Supreme Court of Japan sitting in its Grand Bench.

## Issues

1. Whether Article 9 prohibits Japan from permitting U.S. forces to be stationed in Japan under the U.S.-Japan Security Treaty, thereby rendering the treaty unconstitutional.
2. Whether, if the treaty is unconstitutional, implementing legislation criminalizing trespass on U.S. bases is also unconstitutional.
3. What level of judicial review applies to constitutionality disputes involving foreign affairs and national defense policy.

## Decision

- The Supreme Court Grand Bench reversed the acquittals and remanded for further proceedings.
- The Court held the Security Treaty and stationing of U.S. forces were not clearly unconstitutional under Article 9.
- The Court concluded Japan retains an inherent right of self-defense and may enter mutual security arrangements consistent with Article 9.
- The Court sustained the validity of the special statute protecting U.S. bases because its constitutional predicate (the Security Treaty) was not clearly unconstitutional.
- The Court adopted a highly deferential approach to judicial review in defense and foreign affairs, intervening only for an apparent or clear constitutional violation.

## Legal Principles

- Article 9 renounces aggressive war and the maintenance of prohibited “war potential,” but does not eliminate Japan’s inherent right of self-defense as a sovereign state.
- Mutual security treaties and defensive arrangements, including permitting allied forces to be stationed in Japan, are not unconstitutional per se under Article 9.
- In matters of national defense and foreign affairs, courts should not substitute judicial judgment for political-branch determinations absent a clear and manifest constitutional violation.
- When the underlying security arrangement is not clearly unconstitutional, implementing legislation supporting that arrangement is generally upheld.

## Conclusion

The Supreme Court upheld the constitutionality of the U.S.-Japan Security Treaty against an Article 9 challenge, validated the special base-trespass statute, and limited judicial intervention in defense and foreign policy to cases of clear constitutional incompatibility, reversing the acquittals and remanding for retrial.


Sakata v. Japan (Sunakawa Case), 13 Keishū 3225 (Japan 1959)