This book is designed to remove Peter Kropotkin from the framework of classical anarchism. By focusing attention on his theory of mutual aid, it argues that the classical framing distorts Kropotkin's political theory by associating it with a narrowly positivistic conception of science, a naively optimistic idea of human nature and a millenarian idea of revolution. Kropotkin's abiding concern with Russian revolutionary politics is the lens for this analysis. The argument is that his engagement with nihilism shaped his conception of science and that his expeditions in Siberia underpinned an approach to social analysis that was rooted in geography. Looking at Kropotkin's relationship with Elisée Reclus and Erico Malatesta and examining his critical appreciation of P-J. Proudhon, Michael Bakunin and Max Stirner, the study shows how he understood anarchist traditions and reveals the special character of his anarchist communism. His idea of the state as a colonising process and his contention that exploitation and oppression operate in global contexts is a key feature of this. Kropotkin's views about the role of theory in revolutionary practice show how he developed this critique of the state and capitalism to advance an idea of political change that combined the building of non-state alternatives through direct action and wilful disobedience. Against critics who argue that Kropotkin betrayed these principles in 1914, the book suggests that this controversial decision was consistent with his anarchism and that it reflected his judgment about the prospects of anarchistic revolution in Russia.