A proxy war or proxy warfare is a war in which opposite sides use third parties as substitutes for fighting each other directly. States have sometimes used less powerful states as proxies. Violent non-state actors, mercenaries, and other third parties are more often employed. It is hoped that these groups can strike an opponent without leading to full-scale war. The United States and the Soviet Union used proxies to fight during the Cold War. They tried to increase their influence and diminish each others influence.