"Civil-military relations, which refer to the relationship between the civilian political leadership and the military, have been widely studied due to the latent danger of a state's military usurping control from civilian authorities. As Socrates once said, soldiers protect the state from external threats, but they themselves are also potential threats to society. For this reason, limits must be placed on the military's role within a society, and civilian control of the military has been accepted as a norm within democratic regimes — political leaders set policy (ends), while the military use their military expertise to devise strategies (means) to implement that policy. This is essential for the democratic system, where civilian political leaders exercise the authority delegated to them by the people to rule. Thus, unelected soldiers must obey decisions made by political leaders. To this end, in most democracies civilians hold top national security posts."