The document provides an overview of realism and idealism in international relations. [1] Realism emphasizes that nation-states are motivated by national interests and pursue power, while idealism stresses peace and cooperation between states. [2] The document outlines the key assumptions and types of realism, and discusses thinkers like Thomas Hobbes and the Peloponnesian War. [3] It also defines idealism as promoting universal ethics, peace, and limiting the use of military force between states.