Ranging from global superpowers like the United States and the Soviet Union to regional players like South Africa and Zaire, numerous countries entered the conflict and complicated the situation.  American, Soviet, and Chinese involvement were rooted primarily in the existential Cold War struggle of ideologies and global geopolitics, with economic interests also playing a major role for the United States.  Regional powers were influenced by the superpowers and motivated by a number of other factors as well.  The changing nature of world politics would alter the course of the war and most of the major powers would withdraw from Angola in the late-1980s and early-1990s.