Secrecy and Physics

Secrecy in matters of national defense goes back far past antiquity. But our modern form of national secrecy owes a huge amount to a the large scale, systematic, and technical system of scientific secrecy that began in the Radar and Manhattan Projects of World War II and came to its current form in the Cold War. Here I would like to capture some of this trajectory and to present some of the paradoxes and deep conundrums that our secrecy system offers us in the Post-Cold War world.