INTERNATIONAL law is concerned with persons not only in regard to the establishment of their citizenship, but as concerns their status and legal capacity in foreign countries as well. The latter are to be studied from two aspects: (1) the rules relative to admission to, departure from, and sojourn in the foreign country, and (2) the rules regulating the legal rights and capacities of persons abroad.
Legally every sovereign state has the right to neglect all relations with the outside world, and to forbid any entry of foreigners. Practically, however, such isolation would be inconsistent with the most elementary ideas of international economic relationship, as well as political philosophies. Hence, as a matter of fact, foreigners are ordinarily admitted to states within the Family of Nations. The Soviets recognize this principle, although in the early days of their existence the entry of foreigners was strictly dependent upon treaty agreements.
The early agreements contemplated the admission of a limited number of especially appointed persons only, for the purpose of carrying on trade relations between the Contracting States. To quote Article 4 of the Trade Agreement between the R.S.F.S.R. and Great Britain of March 16, 1921:
"Each Party may nominate such number of its nationals as may be agreed from time to time as being reasonably necessary to enable proper effect to be given to this agreement . . . and the other party shall permit such persons to enter its territories, and to sojourn and carry on trade there, provided that either party may restrict the admittance of any such persons into any specified areas, and may refuse admittance to or sojourn in its territories to any individual who