Leon Trotsky remains the towering figure in the history of revolutionary socialism in the twentieth century. A careful study of his writings is essential for the elaboration of the strategy and tactics of socialist revolution in our epoch, that of imperialist clashes coalescing into a new world war and a worldwide assault on the condition of the working class.

Trotsky's greatest achievement was the founding of the Fourth International (FI) in 1938, after the Third International under Stalin facilitated the coming to power of Hitler in Germany, without a fight by the multi-millioned working class. A principled internationalist, opposed to Stalin's "socialism in one country," Trotsky wrote in the founding document of the FI that "the historical crisis of mankind is reduced to the crisis of the revolutionary leadership."

Written over a forty-year period, the essays in this book are devoted to bringing the rich historical lessons to a new generation of workers and young people, in order to resolve the "historical crisis of mankind."