Sphere of influence, in international politics, the claim by a state to exclusive or predominant control over a foreign area or territory. The term may refer to a political claim to exclusive control, which other nations may or may not recognize as a matter of fact, or it may refer to a legal agreement by which another state or states pledge themselves to refrain from interference within the sphere of influence. As a tool of great power or imperial control, the assertion of sphere of influence can bring order to peripheral areas but can contribute to conflicts when rival powers seek exclusive influence in the same area or when secondary or client states resist subordination.
