Morgenthau outlines the “six principles of political realism” as follows:
• Politics is governed by objective laws which have their root in human nature.
• The key to understanding international politics is the concept of interest defined in terms of power.
• The forms and nature of state power will vary in time, place and context but the concept of interest remains consistent.
• Universal moral principles do not guide state behavior, although this does not rule out an awareness of the moral significance of political action.
• Moral aspirations are specific to a particular nation; there is no universally agreed set of moral principles.
• The political sphere is autonomous (Heywood, 2011).