Spheres
of influence is a collection of allying regions or countries that are
under the rule of a certain nation or organization. The ruler has
economic, political, and to even some extent, cultural influence over
the regions that are under them. The rulers usually have strong
military power which enables them to control the regions under them.
A very good example would be the Greater
East Asia Co-Prosperity Sphere
wherein the Japanese rule over certain Asian countries like Korea,
some countries in South Eas Asia, and even China.