This textbook provides a comprehensive introduction for individuals who are new to the discipline of International Relations or World Politics. It features three distinctive elements. First, it posits that understanding the international political economy is essential before delving into analyses of war and security, emphasizing that economic interdependence, arising from international cooperation, is a central theme in international relations. Second, the textbook recognizes that strategic interaction — where the decisions of one entity and future outcomes depend on the choices of another — is a core component of international relations. It also utilizes four key concepts in its exploration of the field: Us and Others, Disparity and Dissatisfaction, Trust and Distrust, and Legitimacy and Illegitimacy. Lastly, the textbook is attuned to the methodologies of the Social Sciences, including descriptive, causal, and deductive inferences, and it stands out for its commitment to fostering methodological awareness.