On September 6, 1947, the United States Navy launched a captured German V-2 rocket from a ship in the Atlantic — a quiet but consequential act that reordered the logic of military power. What had been a weapon of terror over wartime Europe became, in American hands, a proof of concept for something far more enduring: the idea that destruction could be hidden beneath the sea, patient and invisible. In that single ballistic arc, the foundations of Cold War deterrence were quietly laid.