A sphere of influence refers to a region or area where one country or power exercises a dominant level of control or influence over political, military, or economic developments. For example, during the Cold War, Eastern Europe was within the Soviet Union’s sphere of influence, while Western Europe was under U.S. influence through NATO.

In contemporary times, China’s increasing presence in Southeast Asia and Africa through economic and diplomatic initiatives such as the Belt and Road Initiative can be seen as an effort to expand its sphere of influence. Similarly, Russia views its neighboring countries in the former Soviet bloc as part of its strategic sphere.