AILSA CHANG, HOST:
The U.S. and North Korea appear to be walking back their threats to rain down destruction on one another. Kim Jong Un announced yesterday that he is delaying his decision to fire missiles towards Guam - for now. But the heated rhetoric over the past week has many wondering about the use of nuclear weapons. The only time they've ever been used was by the United States during World War II. Here's President Harry S. Truman after the bombing of Hiroshima.
(SOUNDBITE OF ARCHIVED RECORDING)
HARRY S. TRUMAN: With this bomb, we have now added a new and revolutionary increase in destruction to supplement the growing power of our armed forces. In their present form, these bombs are now in production, and even more powerful forms are in development.
CHANG: The rules for how nuclear weapons are used today have not changed since President Truman's time. So just who is in charge of launching a nuclear attack? That's a question many of you wanted answered this week, and we are putting it to Cokie Roberts in our regular Ask Cokie segment. Good morning, Cokie.
COKIE ROBERTS, BYLINE: Hi, Ailsa. Nice to talk to you again.
CHANG: Nice talking to you too. So here's our first question.
ANNE MOORE: This is Anne Moore from Cypress, Texas. And I wanted to know if Congress has neither declared war nor authorized military action, would an executive order be sufficient to launch nuclear weapons?
ROBERTS: Actually, nothing as formal as an executive order is required. It's simply the president saying that he wants to launch a nuclear attack. Presumably, he says that in a very short period of time after the military has detected a missile launch by a hostile nation. And the president's authority derives from the Atomic Energy Act of 1946, which was passed amid much controversy the year after the bombs were dropped.
CHANG: Wait, what kind of controversy?
ROBERTS: Well, you know, laws are passed in the context of the times.
CHANG: Yeah.
ROBERTS: And the scientists who had worked on the bombs were having enormous qualms about what they had unleashed. And they started lobbying Congress to make sure that the bombs stayed under civilian control. Remember, we talked last week, Ailsa, about Truman reigning in General MacArthur.
CHANG: Right.
ROBERTS: And there was a sense then that the generals were trigger-happy and that they shouldn't have the last word on these massively lethal weapons. So the president has the sole authority over nuclear weapons.
CHANG: Well, that gets us to our next question. Let's give a listen.
THERESA EAMAN: My name is Theresa Eaman, and I'm from Monroe, N.C. Does the president have access to the nuclear codes that he could launch a weapon without additional approval? What safety mechanisms are in place?
ROBERTS: Well, the codes are in what's called the nuclear football. That's the thing that travels with the president everywhere he goes.
CHANG: And it's not shaped like a football, right?
ROBERTS: No, no, it's not. But say the president learned of an attack. The person carrying the football - who's vetted, by the way, by the FBI, the Secret Service and the Department of Defense - would show the president his options, whether he should attack by sea, air or whatever. And then the president has a device, which is called the biscuit, which is like a credit card. And it shows that he's the actual president. And then he gives the order to use the weapons. And he can launch close to a thousand warheads in minutes.
CHANG: Wow.
ROBERTS: After that, there is no veto power. Under the law, the military must carry out the president's order.
CHANG: Wait. But what happens if, say, a president is in no condition to make that kind of decision? Let's say he's drunk or otherwise impaired.
ROBERTS: Well, that's a question that's been asked for decades. And actually, some members of Congress are asking it again. Theoretically, the secretary of defense could refuse to pass the order down the line of command. But that would be illegal - maybe even treasonous.
CHANG: Wow.
ROBERTS: There have been reports in the years since Richard Nixon's death that his secretaries of defense and state, James Schlesinger and Henry Kissinger, were worried about the president's drinking and his general state of mind and that they conspired to make sure that no one carried out the president's orders about nuclear weapons without checking in with one of them. If that's true, it was illegal.
CHANG: That's incredible.
ROBERTS: Yeah.
CHANG: Finally, we have this quick question from Ben Maas in Storm Lake, Iowa. He asks, is it literally a red button that would be pushed?
ROBERTS: No.
CHANG: Actually, I have the same question. No?
ROBERTS: No buttons - no buttons at all of any color. Just the president's word and a biscuit.
CHANG: Thank you so much, Cokie.
ROBERTS: Good to be with you.
CHANG: That's commentator Cokie Roberts. And you can ask Cokie your questions about how politics and government work by emailing us at askcokie@npr.org or by tweeting us with the hashtag, #AskCokie. Transcript provided by NPR, Copyright NPR.