William J. Perry, 19th US Secretary of Defense, is back on Press the Button with our policy director Tom Collina on their recent Reddit "Ask Me Anything" session, which answered questions posted by hundreds of internet users on presidential authority to start a nuclear war and whether the military would refuse a legal order to launch nuclear weapons. Tom and Secretary Perry authored the new book The Button: The New Nuclear Arms Race and Presidential Power from Truman to Trump. Early Warning features Twela Abrahamson-Swan, director of the SHAWL Society, discussing the impact of nuclear weapons production on the lives of Native Americans.