A
military reserve force is a military organization composed of citizens of a country who combine a military role or career with a civilian career. They are not normally kept
under arms and their main role is to be available to fight when a nation mobilizes for
total war or to defend against invasion. Reserve forces are generally not considered part of a permanent standing body of armed forces. The existence of reserve forces allows a nation to reduce its peacetime military expenditures while maintaining a force prepared for war. It is analogous to the historical model of military recruitment before the era of standing armies.