"During the Cold War, nuclear submarines performed the greatest public service of all: prevention of a third world war. History shows that they succeeded: the Cold War ended peacefully, but for security reasons, only now can this story be told. Eric Thompson ... joined the Navy in the last days of Empire, made his first sorties in former World War II submarines and ended up as the top engineer in charge of the Navy's nuclear power plants. Along the way, he helped develop all manner of kit, from guided torpedoes to the Trident guided missile system. ... [He] reveals what it was like to literally have your finger on the nuclear button. In his journey, the author leads the reader through top-secret submarine patrols, hush-hush scientific trials, underwater weapon developments, public relations battles with nuclear protestors, arm-wrestling with politicians, the procedures needed for a nuclear weapon to be fired, and how the Prime Minister informs the submarine they are to do so."--Book jacket.