Who’s at the trigger when the president calls a nuclear strike

WATCH ALL THE STORIES IN OUR "AGING ARSENAL" SERIES:

JUDY WOODRUFF: Over the past eight months, we have aired three stories about America's aging nuclear arsenal.

Tonight, we thought we'd share with you some of the more interesting things we learned along the way.

John Yang has that.

JOHN YANG: Our past stories looked at the debate over rebuilding America's nuclear submarines, missiles and bombs, now that much of the current arsenal is reaching the end of its service life.

And, tonight, to continue our unprecedented look behind the scenes, we meet some of the men and women charged with this great responsibility.

Veteran defense correspondent Jamie McIntyre reported these stories for us, in partnership with the Pulitzer Center on Crisis Reporting.

MAN: All stations, all stations, this is absentee, absentee.

JAMIE MCINTYRE: If the president ever gives the order to unleash nuclear weapons, the men and women whose fingers are on the triggers would hear something like this.

MAN: Yankee, mike. Stand by, uniform.

JAMIE MCINTYRE: It's the sound of an emergency action message. It's only a drill, but in a real-life situation, the highly encrypted message sent to bombers, submarines and missile crews would tell them which war plan to execute and which targets to destroy.

The coded message echoes, because it's sent by many different radios around the world, to ensure that even if the nation were under nuclear attack, at least one of the messages would get through.

The "NewsHour" was granted rare access to America's nuclear war fighters over the past six months. At Minot Air Force base in North Dakota, we spent the day with the airmen who load the B-52 bombers and the crews that fly them.

Chief Master Sergeant Lee Robins is the wing weapons manager.

How can you tell how old it is?

CHIEF MASTER SGT. LEE ROBINS, Wing Weapons Manager, U.S. Air Force: It's pretty easy. So, there is — on the tail number, if we look underneath the letters A.F., this is a 61, so that is when it rolled off the assembly line.

JAMIE MCINTYRE: That makes this aircraft 19 years older than Major Luke Dellenbach, a B-52 commander and instructor pilot.

I asked him about the differences between flying a conventional vs. nuclear mission.

MAJ. LUKE DELLENBACH, Aircraft Commander, U.S. Air Force: For a nuclear mission for us, it's very controlled. It's very scripted. The president doesn't want us doing things that we want to do. There is not inventiveness. It's very much you follow the rules and you follow the procedures and guidelines that we have.

For conventional, it's almost the opposite. We have a lot more flexibility. We can be more innovative. We can hit targets different ways.

JAMIE MCINTYRE: It's a sobering mission, and the venerable B-52 has been updated with modern avionics to carry it out, even though, as the crew is quick to show us, some non-mission-critical systems are an antiquated reminder of its Cold War history.

What do we have?

MAJ. C. RYAN COX, Mission Commander, U.S. Air Force: So, over here, we have the oven. It has two different settings, off and 400 degrees.

JAMIE MCINTYRE: 1960s technology?

MAJ. C. RYAN COX: It still works today. And up here, we have a sextant port (INAUDIBLE) navigation if everything else fails.

JAMIE MCINTYRE: You know how to use a sextant?

MAJ. C. RYAN COX: No. We usually put a GPS antenna out of it if we need it.

(LAUGHTER)

JAMIE MCINTYRE: While bombers crews typically fly at 50,000 feet above the ground, the submariners we visited last summer lurk hundreds of feet below the surface, in this case plying the depths of the Pacific Ocean.

MAN: Dive, dive.

JAMIE MCINTYRE: By far, the stealthiest leg of the nuclear triad, the submarine's unofficial motto is hide with pride.

The USS Pennsylvania's crew spends three months at a time in the cramped confines of the windowless ballistic missile submarine, breathing recycled air and never seeing the sun, that is, unless they are among the chosen few who get to go topside while the sub takes on provisions, an elaborate and highly choreographed ritual on the high seas in which canvas bags of food an supplies are transferred from boat to boat.

While the subs patrol undersea, missileers serve underground. They have to take an elevator 50 to 60 feet down each time they arrive at their jobs. There are 45 launch facilities spread across the America's heartland controlling the intercontinental ballistic missiles, ICBM, buried in silos in fixed, known locations.

MAN: Incoming emergency action message.

JAMIE MCINTYRE: We got to watch two junior officers practicing running through the lengthy checklist to launch nuclear missiles.

To get the launch keys, they must each unlock a padlock. In this training scenario, using unfamiliar locks, a forgotten combination delays a mock launch. In case you're wondering, missileers can't just go rogue. It takes four officers, in two separate launch facilities, to launch a missile after an authentication code is received.

You can't help noticing how young America's nuclear warriors are. First Lieutenant Kathleen Fosterling who commands a two-person missile combat crew, is 27. She works a 24-hour shift eight times a month, waiting for an order she hopes to never receive.

1ST LT. KATHLEEN FOSTERLING, Commander Missile Combat Crew, U.S. Air Force: I wouldn't say it's lonely. Yes, we only work with technically one other person, but we have all the other guys topside. We have — we talk to the other crews at the other capsules constantly.

But our free time, if we have any, not always — sometimes, there is a lot — sometimes, there is not — a lot of people do homework. There is a lot of people in school. We read. We watch TV. We watch movies, hang out with each other. It's not so bad.

(LAUGHTER)

JAMIE MCINTYRE: Do you ever wonder, we ask, what it would be like if she had to turn the launch key for real?

1ST LT. KATHLEEN FOSTERLING: It's hard to think about it, because you don't know what is going to happen in that situation. You just have to do your job. And whatever the outcome is, it is.

JAMIE MCINTYRE: First Lieutenant Fosterling is not alone. A number of nuclear warriors told us it's very hard to think about what it would be like after the unthinkable happens.

JOHN YANG: Now Jamie McIntyre joins us.

Jamie, this was really a remarkable series. You showed us things that we rarely see on television.

I have to ask you, what do you take away from this personally? What was most memorable for you?

JAMIE MCINTYRE: Well, you know, John, one of the things we asked almost all the people we interviewed was, have you ever thought about what would happen if you actually had to employ these weapons? It is the classic unthinkable scenario.

And what we found was that, yes, most of them had thought about it, but they don't dwell on it. These are military people trained to a mission and they think about their part of the mission, and there's not a whole lot of angst of what would happen if they actually were involved in an all-out nuclear exchange.

It was interesting. When we talked to the submarine commander, we said, well, how would you deal with the crew after you have already launched all these missiles and you know that maybe even the end of the world is coming? And he said, well, it would be difficult. Hopefully, he said, there will be some guidance.

JOHN YANG: A little guidance from the Pentagon on it.

And talk about that, because this really is — they are handling the awesome power of nuclear weapons. But it's a job for them. It's their assignment. It's their day-to-day assignment.

JAMIE MCINTYRE: Well, I mentioned this in the piece, that one of the things that really struck me was how young everybody was, and how they're focused on their mission.

The young 1st lieutenant that we met in the missile silo, 1st Lieutenant Kathleen Fosterling, so she's very young and she's commanding this two-person crew, but yet — and she's in this tiny room underground in a windowless room every day. And one of the things that struck you is that you had the — you see how they personalize their life.

So, for instance, those locks — and you saw the sequence in the story where the training scenario, they can't get the lock open because they're using a training lock. In real life, they all use their own personal padlocks. And she had plastered hers with Hello Kitty stickers, which seemed to be sort of this juxtaposition of the fact that they're — they're conducting this awesome mission, but, at the same time, it is a job, and they just need to have some sort of human interaction and think of it as something that they just do every day.

JOHN YANG: Just personalizing their workspace.

Jamie McIntyre, remarkable reporting. Thank you very much.

JAMIE MCINTYRE: Thank you.