A U.S. citizen who is a resident or citizen of a foreign country may be subject to compulsory military service in that country. Although the United States opposes service by U.S. citizens in foreign armed forces, there is little that we can do to prevent it since each sovereign country has the right to make its own laws on military service and apply them as it sees fit to its citizens and residents.
Such participation by citizens of our country in the internal affairs of foreign countries can cause problems in the conduct of our foreign relations and may involve U.S. citizens in hostilities against countries with which we are at peace. For this reason, U.S. citizens facing the possibility of foreign military service should do what is legally possible to avoid such service.
Federal statutes long in force prohibit certain aspects of foreign military service originating within the United States. The current laws are set forth in Section 958-960 of Title 18 of the United States Code. In Wiborg v. U.S., 163 U.S. 632 (1985), the Supreme Court endorsed a lower court ruling that it was not a crime under U.S. law for an individual to go abroad for the purpose of enlisting in a foreign army; however, when someone has been recruited or hired in he United States, a violation may have occurred. The prosecution of persons who have violated 18 U.S.C. 958-960 is the responsibility of the Department of Justice.
Although a person's enlistment in the armed forces of a foreign country may not constitute a violation of U.S. law, it could subject him or her to Section 349(a)(3) of the Immigration and Nationality Act [8 U.S.C. 1481(a)(3)] which provides for loss of U.S. nationality if an American voluntarily and with the intention of relinquishing U.S. citizenship enters or serves in foreign armed forces engaged in hostilities against the United States or serves in the armed forces of any foreign country as a commissioned or non-commissioned officer.
Loss of U.S. nationality was almost immediate consequences of foreign military service and the other acts listed in Section 349(a) until 1967 when the Supreme Court handed down its decision in Afroyim v. Rusk, 387 U.S. 253. In that decision, the court declared unconstitutional the provisions of Section 349(a) which provided for loss of nationality by voting in a foreign election. In so doing, the Supreme Court indicated foreign election. In so doing, the Supreme Court indicated that a U.S. citizen "has a constitutional right to remain a citizen... unless he voluntarily relinquishes that citizenship."
Further confirmation of the necessity to establish the citizen's intent to relinquish nationality before expatriation will result came in the opinion in Vance v. Terrazas, 444 U.S. 252 (1980). The Court stated that "expatriation depends on the will of the citizen rather than on the will of Congress and its assessment of his conduct." The Court also indicated that a person's intention to relinquish U.S. citizenship may be shown by statements or actions.
Military service in foreign countries usually does not cause loss of citizenship since an intention to relinquish citizenship normally is lacking. Service as a high-ranking officer, particularly in a policy-making position, could be viewed as indicative of an intention to relinquish U.S. citizenship.
Pursuant to Section 351(b) of the Immigration and Nationality Act, a person who served in foreign armed forces while under the age of eighteen is not considered subject to the provisions of Section 349(a)(3) if, within six months of attaining the age of eighteen, he or she asserts a claim to United States citizenship in the manner prescribed by the Secretary of State.