The jus soli principle is the basis of the law of Great Britain and the United States; the jus sanguinis rule prevails in Germany, Austria, France, Hungary, Switzerland and other states. Few states, however, apply either principle ex clusively. Thus according to American law children born abroad of fathers who are citi zens of the United States and who have them selves resided here are deemed to be citizens of the United States. Likewise, according British law, children born abroad of British subjects are treated as natural-born British sub jects. Thus both countries, although following in general the doctrine of the jus soli, have adopted the jus sanguinis principle for deter mining the status of children born abroad of citizen parents. In many other states a mixed system prevails. Thus according to French law while all children born of French parents any where in the world are deemed to be French citizens, those born in France of alien parents and not domiciled in France at the age of their majority are regarded as foreigners. A child, therefore, born' in the United States of French parents would be a citizen of the United States jure soli, but a citizen of France jure sanguinis. We have here a case of double nationality, due to the existence of conflicting rules by which citizenship is determined. In practice the con sequences of such conflicts are usually avoided by the policy of states in refraining from as serting their claims in such cases so long as the person whose nationality is in dispute re mains outside their jurisdiction. To avoid cases of double nationality it would be neces sary to assimilate all the various systems for determining national character, an ideal which, however desirable, is not likely to be realized.
In time of war the national character of an individual may not be the same as that of his political character. It may be that of his domi cile or his place of business. Thus if he is domiciled in an enemy country or has a house of trade therein he may for certain purposes be an alien enemy to his own country.
Concerning the test for determining the na tionality of ships in time of war there has been much diversity of opinion. The continental European view has generally been that national character in such cases should be determined by the nationality of the owner; English and American opinion, however, has regarded the flag which the ship is entitled to fly as the proper test. The question was considered at the London Naval Conference of 1908-09, and a compromise was reached by the adoption of the rule that the nationality of a vessel should be determined by the flag which it is entitled to fly (article 57) and that the enemy or neutral character of goods found on board an enemy vessel should be determined by the neutral or enemy character of the owner (article 58). During the recent World War, however, the British government rejected the former rule and put into effect the rule that the neutral or enemy character of a vessel should be deter mined by the nationality of the owner. See also ALLEGIANCE and CITIZENSHIP IN THE UNITED STATES. For bibliography see article CITIZENSHIP IN THE UNITED STATES.