A police force, domestic or international, must meet two requirements: it must be reliable, and it must be effective. While obviously it cannot be effective if it is not reliable, it can be reliable without being effective, and it is for this reason that the two prerequisites must be distinguished. A police force, in order to be reliable, must be loyal to the political authorities and share their conceptions of law and justice. A police force, in order to be effective, must stand in a certain relation of power to that fraction of the population which is likely to call forth police action by breaking the law.
1 Hans J. Morgenthau is Director of the Center for Study of American Foreign and Military Policy of the University of Chicago.