- Statism: Realists believe that nation states are the main actors in international politics. As such it is a state-centric theory of international relations. This contrasts with liberal international relations theories which accommodate roles for non-state actors and international institutions. This difference is sometimes expressed by describing a realist world view as one which sees nation states as billiard balls, liberals would consider relationships between states to be more of a cobweb.
- Survival: Realists believe that the international system is governed by anarchy, meaning that there is no central authority. Therefore, international politics is a struggle for power between self-interested states.
- Self-help: Realists believe that no other nation states can be relied upon to help guarantee the state's survival.