What nationality must a sailor be to reenlist according to eligibility criteria?

For a sailor to be eligible to reenlist, they must be a U.S. Citizen. This requirement stems from the need for service members to have a strong and enduring commitment to the U.S. and its military values, which is embodied in citizenship. U.S. citizens are given full rights and responsibilities, including the obligation to serve in the defense of the nation if called upon. While permanent residents and naturalized citizens can serve in the military, only U.S. citizens, who have gone through the complete process of naturalization and have the rights associated with full citizenship, are eligible to reenlist without facing additional scrutiny or requirements that may apply to other statuses. Dual nationals may hold a second nationality, but the emphasis is on the requirements set forth for U.S. military service, which primarily favors full citizenship for reenlistment.