For much of the 20th century, the Soviet Union was veiled behind an Iron Curtain of secrecy and oppression orchestrated by the Communist party and intelligence services like the KGB. While the public knew of the KGB as a spy agency abroad, few glimpsed its extensive surveillance and suppression of dissent within Soviet borders. This book documents accounts of KGB assassination teams, infiltration operations, staged provocations, planted propaganda, and the capture of double agents abroad. But it also uncovers widespread interference in culture, media, religion, and daily life behind the Soviet border. The aim is not just to recount historical events but to offer an inside story that goes beyond the superficial understanding of covert operations. It is an exploration of the motivations, the betrayals, and the sacrifices made by those who operated in the shadows, shaping the course of history with every classified mission.