This book examines critically, in historical perspective, the evolution of Marxism, from classical theories to the Neo-Marxist currents p;acing the accent on the ways the US was affected by these leftist ideologies. The book analyses the main ideas regarding the various fashions of socialism, like international socialism, national socialism and democratic socialism, concluding that the Marxist ideologies never worked anywhere. The author reproduces, in translation, interviews with Lenin, Stalin and Hitler, giving the reader a unique opportunity to look into the psyche of those despots who defined the 20th century as the century of genocide.