Operation Tannenbaum

Operation Tannenbaum: The Nazi Plan to Invade Switzerland by Tom Ridley is a meticulous investigation into one of the least-known military operations of the Second World War-a campaign planned in secret, and never executed. In the summer of 1940, as German divisions stood astride Europe, the Wehrmacht drafted detailed invasion plans for neutral Switzerland: troop movements through the Jura, armored columns across the Rhine, and airstrikes over the mountain passes. The objective was clear-secure the heart of Europe and its strategic railways, gold reserves, and industrial capacity.

Drawing on declassified German and Swiss archives, wartime intelligence files, and on-site fieldwork in the Alpine fortresses of the Réduit national, Ridley reconstructs the plan's conception, its logistical challenges, and the silent countermeasures that turned Switzerland into a fortress of rock and ice. Through the eyes of generals, spies, and mountaineers, Operation Tannenbaum reveals how geography, deterrence, and calculation shaped one of history's strangest standoffs-a battle that existed only on maps, yet shadowed the entire war.

Written with precision and restraint, Ridley's account evokes the cold logic of wartime planning and the enduring power of terrain. It is a story of strategy without combat, resistance without victory parades, and a small nation's survival amid the machinery of total war.