In the days following the atomic bombings of Hiroshima and Nagasaki, the Japanese surrendered unconditionally. But even before the surrender, the US had begun a secret propaganda campaign to celebrate these weapons as the ultimate peacekeepers hiding the true extent and nature of their devastation. The cover-up intensified as Americans closed the atomic cities to Allied reporters, preventing information from leaking about the horrific and lasting effects of radiation that would kill thousands of people during the months after the blast. For nearly a year, the cover-up worked until New Yorker journalist John Hersey got into Hiroshima and reported the truth to the world. As Hersey and his editors prepared his article for publication, they kept the whistleblowing story secret even from most of their New Yorker colleagues. When the magazine published 'Hiroshima' in August 1946, it became an instant global sensation, and inspired pervasive horror about the weapons that had been covertly waged in America's name. Since 1945, no nuclear weapons have ever been deployed in war, partly because Hersey alerted the world to their true, devastating impact. This knowledge has remained among the greatest deterrents to using them since the end of World War II.