(c) Other states follow sometimes the jus sanguinis, sometimes jus soli, and sometimes modifications of these laws. The laws of Belgium and Spain regard the child of an alien as an alien, though on attaining majority the child may choose the citizenship of the country of his birth. The French laws of June 26-28, 1889, and July 22, 1893, consider as subjects the children born abroad to French citizens, also the children of foreigners born in France, unless these children within one year after attaining majority elect the nationality of their parents. Most states allow the descendants born to foreigners sojourning within their limits to elect their allegiance on attaining majority. Switzerland, however, strongly maintains the jus sanguinis, without according any choice to the descendants born to foreigners within her limits, or to her own subjects born abroad except by formal renunciation of citizenship. Thus the child of a citizen of Switzerland born in France would be by French law a citizen of France, and by Swiss law a citizen of Switzerland.
By the law of Germany, a citizen of Germany sojourning more than ten years abroad without registration at his consulate loses his German citizenship, without necessarily acquiring the citizenship of the country of his sojourn, thereby becoming heimatlos, or a "man without a country."
At the present time the laws in regard to descendants born to parents sojourning in a foreign state show the widest diversity and give rise to unfortunate complications.[163]
[§ 59. Jurisdiction by Virtue of Acquired Nationality]
The jurisdiction of a state extends to those who voluntarily acquire its citizenship.
(a) A woman in most states by marriage acquires the nationality of her husband. In some of the South American states the husband acquires the citizenship of his wife. By the law of Belgium, Aug. 6, 1881, and by the law of France, June 26, 1889, it was made easier for foreigners who had married women natives of those states to acquire Belgian or French nationality respectively. The United States law, while holding that a woman marrying a citizen of the United States acquires his nationality, does not hold that an American woman on marrying a foreigner thereby becomes expatriated, unless she takes up her residence in her husband's state.[164]
(b) A state may acquire jurisdiction over persons by naturalization, which is an act of sovereignty by which a foreigner is admitted to citizenship in another state. The method of naturalization is in accord with local law and varies greatly in different states.[165] The law of the United States prescribes that Congress has power "to establish an uniform rule of naturalization."[166] The foreigner desiring naturalization in the United States must declare on oath before a court after three years of residence in this country, his intent to become a citizen, and, after he has remained here two years longer he must take an oath of allegiance to the United States and of renunciation of his former country. An alien who has resided in the United States the three years next preceding the attaining of his majority and who continues to reside in this country at the time of his application, may, after reaching twenty-one years of age, and after residing here five years including the three years of minority, become a citizen by making a declaration at the time of admission.[167]
(c) A state may acquire jurisdiction over persons by annexation of the territory upon which they reside. The territory may be acquired by cession, exchange, purchase, conquest, etc. The conditions of the transfer of allegiance from the state formerly possessing the territory is usually fixed by the treaty. This transfer is known as collective naturalization.
Ordinarily a right to choose the allegiance to either state is left to the inhabitants of an annexed territory. Removal from the new jurisdiction is usually required if the inhabitant does not choose to change his allegiance. If the inhabitant does not take any action, it is held that he thereby tacitly transfers his allegiance unless there are special treaty provisions.[168]
(d) The effect of naturalization, whatever the method, is to make the person a citizen of the state into which he is admitted, and over him that state has jurisdiction in all places outside the jurisdiction of the state whose allegiance he has forsworn.