With the flurry of talks with North Korea and the fallout from the U.S. withdrawal from the Iran nuclear deal, nuclear weapons have become a major topic of discussion in recent months. But secrecy abounds: Who has what weapons? How many? How much damage could they do?
Kristensen sat down with The Washington Post to discuss how the United States’s nuclear capabilities stack up with the rest of the world, and potential problems down the road. The questions and answers have been edited for brevity.
Why do you have to come up with estimates about the stockpiles? Why don’t we have hard data?
KRISTENSEN: Countries like to keep nuclear weapons data secret. That’s the tendency. It varies from country to country a lot. In the United States, there’s a lot of information available. It wasn’t always like that. There has been a process in the United States where the government has gradually become more at ease, if you will, with disclosing a certain amount of information. There are still secrets, by all means. But a lot of information can come out.
In other countries, it’s not like that. So it varies tremendously from country to country. In some countries, even if you try to collect this information, you go to jail. So we find ourselves in a very interesting role where for countries like China, we can provide information to people in China that want to have a discussion about nuclear weapons, because they can use information coming from outside. They don’t have to do their own homework.
One thing that really sticks out on your bio was that in 2010 you almost completely accurately estimated the U.S. stockpile. How much were you off on that?
KRISTENSEN: 13 weapons out of a stockpile of 5,113. But of course that didn’t come about because of one person doing some work over six months. It came about because many, many people over the years have been digging in and gleaning information from congressional hearings, budget documents, declassified documents that were released under the Freedom of Information Act. And so I was sort of standing on the shoulders of the giants that have created the methodology to do this and just happened to get really, really close to the real number, this top secret number, when the Obama administration in 2010 finally decided to declassify the actual number of nuclear warheads in the U.S. military stockpile.
So that was the number then, and now it has changed?
KRISTENSEN: That was the number then. Since then, they have reduced more. We’re down to about 4,000 now. There’s always been these fluctuations in the nuclear stockpile, but since the end of the Cold War, the trend has been very consistent going south. Fewer and fewer nuclear weapons. Now it’s sort of leveling out a bit and it’s sort of part of a broader trend, if you will, of nuclear reductions worldwide, where it is if the nuclear weapon states are sort of slowing down the disarmament process and are beginning to look at the long term and seeing, how do we want to exist as nuclear weapon states 20, 30 years from now? And what’s going to be the role of nuclear weapons in the world at that time? So there’s a lot more reluctance to progress toward zero these days than there was just 10 years ago.
There is a dilemma here for the countries to figure out the international security order as we progress down to deep cuts and eventual elimination, potentially. So that’s a really tough issue. But what we’re seeing now is also that we have an up-flare of an adversarial relationship again, most dramatically illustrated by the deterioration of relations between Russia and the West. We are back in a real Cold War type adversarial relationship again. It’s not at the scale or intensity of the Cold War, but it has all the characteristics.
Could you talk about the nuclear triad, who still maintains it and why?
KRISTENSEN: The United States has a triad of strategic nuclear forces. That means we have a land-based ballistic missile force, long-range ballistic missiles. They are in silos in the Midwest. We have about 400 of those silos loaded right now with long-range ballistic missiles. Each of those missiles currently carries one nuclear warhead, but some of them can be uploaded to carry more if we need them to. They have such a long range, they can reach anywhere on the planet where they need to go. That means in Russia, China, North Korea, wherever.
Then we have a second leg, which is the ballistic missile submarine force at sea, on board strategic submarines, nuclear powered submarines, very big ships that dive and disappear in the ocean for three months. And their role, essentially, is ultimately to hide so that if an adversary decided to conduct a first strike and try to wipe out everything on land, there was no way they could avoid a devastating retaliatory strike from those submarines.
They also have a third leg, which is the air leg, which is long-range strategic bombers. They can carry a variety of weapons, gravity bombs of different kinds, but also long-range cruise missiles. So either they can fly all the way into their target and drop a gravity bomb on it, or they can loiter off the coast and employ their nuclear cruise missiles from those positions and they will they find their way into their targets.
They also have a fourth leg we don’t normally hear about when we talk about triads. There’s also a leg that is a nonstrategic leg, a tactical leg. It consists of shorter-range fighter aircraft and shorter-range missile systems that can for example go on ships and submarines. They may be designed to blow up other ships or attack land targets. Or the Russians, for example, today still have nuclear torpedoes for their submarines that could be used to shoot other submarines, but with nuclear explosives.
Is cost one reason that some countries don’t maintain nuclear triads, and how has that discussion gone in the U.S.?
KRISTENSEN: Cost is important, but by and large, countries make the sacrifice they need to make if they really think it’s important. The thing with nuclear forces is that they’re very expensive to develop: you have to go through a very long testing program, both for delivery systems and for the warheads themselves, command and control, all these elements that constitute a nuclear posture. And that costs a lot of money to develop. Once you have it, you can maintain it at much less of a cost. You need to overhaul it from time to time.
But if you look at the U.S. nuclear arsenal today compared with what the entire defense budget costs, it’s only a small portion of it. And so there are a lot of people who fall for the temptation to say, see, nuclear weapons are very cheap. So we shouldn’t worry about a modernization program. But that’s not exactly how it works. Any country doesn’t want just nuclear weapons. They want a full military, and nuclear weapons are not very useful because you can’t use them. So you need to have them in the background, so to speak. So you don’t want too much nuke and you don’t want too much nuke to eat up too much of the total defense budget, because then you have to take that money from other conventional programs that might actually be more usable and more vital for the military operations you’re planing to do.
So what we’re seeing right now is that, in the case of the United States, the share of nuclear weapons eat up something in the order of about 4 percent of the defense budget. Because of the modernization program we’ve set in motion, that might increase to about 6, 7, 8 percent in the next decade. So we hear this argument a lot that, oh, it’s very cheap, but it actually creates some serious problems for defense planning.
In your analysis, is the path we’re on a sustainable one?
KRISTENSEN: The current modernization program, to the best we can see, is not sustainable economically. It’s not that the United States couldn’t pay for all of those modernizations if it really wanted to, of course it could. But it would have to take that money from somewhere else. So we’d have to cut some conventional programs and use that money on nuclear instead. And that’s a huge dilemma inside military planning.
So what’s happening now is that there are so many warning signs already that in the ’20s, the cost of the nuclear modernization program is going to force cuts elsewhere in the defense budget, if you want to pay for it. So right now there are people who are out saying, well, why don’t we adjust the nuclear modernization program now, so we don’t have to make these catastrophe cuts later in that may mess up a program or create confusion about our posture and all these types of things.
But we have a very die-hard nuclear advocacy group or community right now that, every time they go to Congress and testify about the nuclear modernization program, it’s like, “Oh no, this is the only one, this is all we can do. Oh no, we can pay for it, it’s only a small portion of defense budget.” They just keep perpetuating this and all the warning signs are out that there are going to be some nasty adjustments that have to be made.