SPHERES OF INFLUENCE. "Spheres of influence," "spheres of action, "spheres of interest," "zones of influence," "field of operations," "Machtsphare," "Interessensphare," are regions as to which nations have agreed that one or more of them shall have exclusive liberty of action. These phrases became com mon after 1882, when the "scramble for Africa" began.
Among treaties defining such spheres are the following : Great Britain and Portugal as to Africa, Aug. 20, 189o, Nov. 1890 and June I1, 1891. Great Britain and France as to Upper Niger, Jan. 20, 1891; Nov. 15, 1893, as to Lake Chad. Great Britain and France as to Siam, Jan. 15, 1896. The two Govern ments engage to one another "that neither of them will, without the consent of the other in any case or under any pretext, advance their armed forces into the regions, etc." They also engage not to acquire within this region any special privilege or advantage which shall not be enjoyed in common, or equally open to Great Britain and France or their nationals and dependants. Great Britain and Italy as to Africa, April 15, 1891; May 5, 1894, as to region of the Gulf of Aden. Congo and Portugal, May 25, 1891, as to "spheres de souverainete et d'influence" in the region of Lunda. Great Britain, Belgium and Congo, May 12, 1894, as to the sphere of influence of the independent Congo State. Great Britain and Ger many, July i, 1890 and Nov. 15, 1893, as to East and Central Africa. Great Britain and Russia as to the spheres of influence to the east of Lake Victoria in the Pamir region, March II, Being the result of treaties, arrangements as to spheres of influ ence bind only the parties thereto. As Olney, in his correspon dence with Lord Salisbury in regard to Venezuela, remarked: "Arrangements as to spheres of influence are new departures, which certain great European Powers have found necessary and convenient in the course of their division among themselves of great tracts of the continent of Africa, and which find their sanc tion solely in their reciprocal obligations" (United States No. 2,
1896, p. 27). Some treaties declare that the arrangement shall not affect the rights of other powers (Stoerck, Recueil, xvi. p. 932). Hinterland.-Claims somewhat similar to these embrace hinterland. Sometimes it is called the "doctrine of contiguity," or "droit de vicinite, de priorite, de preemption ou d'enclave." The occupation of the mouth of a river is constructive occupation of all its basin and tributaries.
A State, having actually occupied the coast, may claim to reserve to itself the right of occupying from time to time territory lying inland (hinterland). In the discussions as to the western boundary of Louisiana between the commissions of the United States and Spain, as to Oregon, as to the claims of the Portuguese in East Africa, and as to the boundaries of Venezuela, the question of the extent of the rights of the discoverer and occupier came up. Lord Salisbury referred to "the modern doctrine of hinterland with its inevitable contradictions" (United States, No. 2, 1896, p. 12). Certainly it is inconsistent with the doctrine, more and more received in recent times, that effective possession is necessary to found a title to sovereignty or control. The doctrine of the hinterland is likely to become less important, now that Africa has been parcelled out. See MANDATE, PROTECTORATE, SOVEREIGNTY.