Continuing our series on international law and citizenship, we introduce the book International Law (1904) by John Westlake, Professor of International Law, Cambridge University. The section on citizenship is very long and the following is but a small part, selected for its particular relevance from Chapter 10.
Who are Nationals Jus soli and jus sanguinis
Historically nationality arose out of allegiance. The sovereign lords in the dealings between whom international law had its origin belonged to a system of which the dominant character was feudal and in feudalism the personal relation of a man to his lord was blended with the territorial relation of a fief to the lordship of which it was held. By virtue of the latter the personal relation to the lord was imposed on all natives of the fief or of the country considered as a collection of fiefs and this jus soli was not inconvenient because few persons were to be met with in any country who had not been born in it except traders and other obviously casual visitors. It was therefore on birth on the soil or on certain circumstances equivalent to birth on the soil that the character of a natural born subject primarily depended. By the common law of England which fairly represents the old common law of western and central Europe on the matter allegiance was due to the king from all persons born on land within his dominions with the exceptions presently to be mentioned or in foreign harbours on board an English ship of war or packet enjoying the immunities of a ship of war or at sea on board an English ship and from children born abroad to a duly accredited English ambassador or minister, but not from children born on foreign soil to English soldiers or sailors….
As a matter of clear history the way in which the jus sanguinis was introduced into the European law of nationality by the side of the jus soli was not that of allowing the character resulting from either to be disclaimed because it conflicted with that resulting from the other. The jus sanguinis makes its appearance as enlarging not the choice of the individual but the grasp of the state….
In America there has not been the same tendency to adopt the jus sanguinis as in Europe because the states of that continent have to deal with and even invite a great immigration which they cannot safely allow to remain alien nor do they like to clog the advantages which they offer to immigrants with a necessity for the children born after their arrival to opt or be naturalised….
In the United States the relation of a citizen to the Union was at first founded on his being a citizen of one of the component states but this was altered by section 1992 of the revised statutes enacted in 1866 and the fourteenth amendment of the constitution ratified in 1868. By the former all persons born in the United States and not subject to any foreign power excluding Indians not taxed are declared to be citizens of the United States. By the latter all persons born or naturalised in the United States and subject to the jurisdiction thereof are citizens of the United States and of the state in which they reside. There was thus introduced an independent citizenship of the United States the persons possessing it being distributed among the several states by residence just as the subjects of the United Kingdom are distributed among the British dominions by domicile. The conditions for possessing this citizenship are to be found in the legislation which introduced it which it will be observed incorporates the English common law doctrine of the jus soli handed on to the Union through the states modified however by a declaration of congress in 1868 that the right of expatriation is a natural and inherent right of all people indispensable to the enjoyment of the right of life liberty and the pursuit of happiness. The true conclusions from these data appear to be that when the father has domiciled himself in the Union he has exercised the right of expatriation claimed for him by congress and that his children afterwards born there are not subject to any foreign power within the meaning of section 1992 but are subject to the jurisdiction of the United States within the meaning of the fourteenth amendment therefore are citizens but that when the father at the time of the birth is in the Union for a transient purpose his children born within it have his nationality and probably without being allowed an option in favour of that of the United States. And these conclusions appear to be in accordance with the practice of the United States executive department.