A fault line war is one that takes place between two or more identity groups (usually religious or ethnic) from different civilizations. It is a communal conflict between states or groups from different civilizations that has become violent. These wars may take place between states, between nongovernmental groups, or between states and nongovernmental groups. Most often, the issue in a fault line war is often territory, but it could also be over the control of people. Such wars within states may involve groups that are predominantly located in different territories or groups that are intermixed. In the latter, violence often erupts periodically.