This book addresses three innovative aspects for the study of International Relations: first, proposes a novel theoretical-methodological framework for the study of national power, and based on this, a quantitative analysis technique is formulated that allows us to study the evolution of state power over almost five decades. Second, states play a fundamental role in the international system, which is why the study of their roles in the world cannot be limited to old, insufficient, and contradictory categorizations. Having new categories of states becomes an even more urgent task in the rapidly changing international order than it is today. This book proposes nine categories of powers and states that cover all the countries that currently exist. Third, the international geostructure of world power is proposed, which represents a new theoretical notion that helps to explain how the international insertion of states and their possibilities of action are conditioned by the unequal distribution of national power and by their structural positioning in the international system. This book is for all students of International Relations, academics, and people who want to understand national power as a fundamental factor in relations between countries.