参考資料:Is a U.S. military base overseas considered U.S. territory? No. While the U.S. military base may be controlled by the U.S. military via agreement with the host country, the land remains the sovereign territory of the host country. (travel.state.gov/content/travel/en/records-and-authentications/requesting-a-vital-record-as-a-u-s--citizen/faqs.htmlから)