In Politics Among Nations, Morgenthau defined international politics as “the struggle for power” and “power politics.” “The aspiration for power,” he wrote, “is “the distinguishing element of international politics.” “The struggle for power,” he continued, “is universal in time and space and is an undeniable fact of experience.”
He set forth six principles of political realism:
1. Politics is governed by objective laws that have their roots in human nature.
2. Statesmen conduct themselves in terns of interest defined as power.
3. Interest determines political conduct within the political and cultural context which foreign policy is formulated.
4. Prudence is the supreme virtue in international politics.
5. Nations are entities that pursue their interests as defined by power and should not be judged by universal moral principles.
6. Political realism rejects the legalistic-moralistic approach to international politics.