Analysing Soviet economic history through the lens of Marx's critique of political economy, this book argues that the Soviet Union was a young capitalist country and, further, explains the collapse of the Soviet Union as the result of a capitalist crisis. This book provides a comprehensive overview of the Soviet economy through a Marxist lens, and provides a digestible definition of the capitalist mode of production according to Marx, refuting criticism of his thought based on association with the USSR. This book also refutes other theories about the Soviet Union, such as the theory of a degenerated workers' state, theories of the Soviet Union having a new mode of production, and even other theories of capitalist USSR, as inadequate because they take the Soviet economy to be 'superior' in some way and therefore cannot explain the Soviet economy's collapse. The goal is not to unearth, collect, and present new data on the Soviet economy but, rather, a Marxist analysis of the Soviet economy based on a synthesis of existing empirical studies. In doing so, the books shines a light on the political debate around the nature of the USSR. The book will be of interest to academic and non-academic Marxists alike in economics, politics, sociology, history and beyond.