Perry’s heard the story of Richard Nixon’s final days in the White House, when Defense Secretary James Schlesinger supposedly told generals that any nuclear strike order from the clearly distressed president be run by him first.

But that’s not really the way it works, Perry said.

“The order can go directly from the president to the Strategic Air Command. The defense secretary is not necessarily in that loop. So, in a five- or six- or seven-minute kind of decision, the secretary of defense probably never hears about it until it’s too late. If there is time, and if he does consult the secretary, it’s advisory, just that,” Perry explained. “Whether [the president] goes with it or doesn’t go with it—[the secretary] doesn’t have the authority to stop it.”