It proceeds in an atmosphere where peace exists and where the former combatants minimally prefer peace to continued war. Peace-enforcement, as it is used by the United States Joint Chiefs of Staff, entails the physical interposition of armed forces to separate ongoing combatants to create a cease-fire that does not exist. Boutros-Ghali, on the other hand, uses the term to refer to actions to keep a cease-fire from being violated or to reinstate a failed cease-fire.