The Washington Post reported yesterday that North Korea has a large stockpile of compact nuclear weapons that can arm the country’s missiles, including its new intercontinental ballistic missiles that are capable of hitting the United States. That’s another way of saying: game over.
There are really two assessments in the Post’s report. One, dated July 28, is that the intelligence community — not just the Defense Intelligence Agency, contrary to what you may have heard — “assesses North Korea has produced nuclear weapons for ballistic missile delivery, to include delivery by ICBM-class missiles.” The other assessment, published earlier in July, stated that North Korea had 60 nuclear weapons — higher than the estimates usually given in the press. Put them together, though, and its pretty clear that the window for denuclearizing North Korea, by diplomacy or by force, has closed.
These judgments are front-page news, but only because we’ve been living in collective denial. Both intelligence assessments are consistent with what the North Koreans have been saying for some time, for reasons I outlined in a column here at Foreign Policy immediately after the September 2016 nuclear test titled, “North Korea’s Nuke Program Is Way More Sophisticated Than You Think: This is now a serious nuclear arsenal that threatens the region and, soon, the continental United States.”
Authors rarely get to pick titles, and almost never like them, but I think the editors at FP got this one about right. It is about as subtle as a jackhammer, although even so the message didn’t seem to sink in.
Let’s walk through the evidence.
North Korea has conducted five nuclear tests. That is really quite a lot. Looking at other countries that have conducted five nuclear tests, our baseline expectation for North Korea should be that it has a nuclear weapon small enough to arm a ballistic missile and is well on its way toward testing a thermonuclear — yes, thermonuclear — weapon.
A lot of people got the wrong idea after North Korea’s first nuclear test failed, and subsequent nuclear tests seemed smaller than they should be. There was a common view that the North Koreans, well, kind of sucked at making nuclear weapons. That was certainly my first impression. But there was always another possibility, one that dawned on me gradually. According to a defector account, North Korea tried to skip right toward relatively advanced nuclear weapons that were compact enough to arm ballistic missiles and made use of relatively small amounts of plutonium. That should not have been surprising; both Iraq and Pakistan similarly skipped designing and testing a more cumbersome Fat Man-style implosion device. The disappointing yields of North Korea’s first few nuclear tests were not the result of incompetence, but ambition. So, while the world was laughing at North Korea’s first few nuclear tests, they were learning — a lot.
And then there is the issue of North Korea’s nuclear test site. North Korea tests its nuclear weapons in tunnels beneath very large mountains. When my research institute used topography data collected from space to build a 3-D model of the site, we realized that the mountains are so tall that they may be hiding how big the nuclear explosions are. Some of the “disappointments” may not have been disappointments at all, and the successes were bigger than we realized. I think the best interpretation of the available evidence is that North Korea accepted some technical risk early in its program to move more quickly toward missile-deliverable nuclear weapons.
The fact that North Korea’s nuclear weapons used less fissile material than we expected helps explain the second judgment that North Korea has more bombs than is usually reported. The defector claimed that North Korea’s first nuclear weapon contained only 4 kilograms of the limited supply of plutonium North Korea made, and continues to make, at its reactor at Yongbyon. (For a long while, experts claimed the reactor was not operating when thermal images plainly showed that it was.) The North Koreans themselves claimed the first test used only 2 kilograms of plutonium. Those claims struck many people, including me, as implausible at first. But they were only implausible in the sense that such a device would probably fail when tested — and the first North Korean test did fail. The problem is North Korea kept trying, and its later tests succeeded.
We also must take seriously that North Korea has perhaps stretched its supply of plutonium by integrating some high-enriched uranium into each bomb and developing all-uranium designs. North Korea has an unknown capacity to make highly enriched uranium. We’ve long noticed that the single facility that North Korea has shown off to outsiders seems smaller than North Korea’s newly renovated capacity to mine and mill uranium; we naturally wondered where all that extra uranium is going. (My research institute thinks it might be fun to estimate how much uranium North Korea enriches based on how much it mills, if you know anyone with grant money burning a hole in her pocket.)
Unless the intelligence community knows exactly where North Korea is enriching uranium and how big each facility is, we’re just guessing how many nuclear weapons the country may have. But 60 nuclear weapons doesn’t sound absurdly high.
The thing is, we knew all this already. Sure, sure it isn’t the same when I say it. I mean, I am just some rando living out in California. But now that someone with a tie and real job in Washington has said it, it is news.
The big question is where to go from here. Some of my colleagues still think the United States might persuade North Korea to abandon, or at least freeze, its nuclear and missile programs. I am not so sure. I suspect we might have to settle for trying to reduce tensions so that we live long enough to figure this problem out. But there is only one way to figure out who is right: Talk to the North Koreans.
The other options are basically terrible. There is no credible military option. North Korea has some unknown number of nuclear-armed missiles, maybe 60, including ones that can reach the United States; do you really think U.S. strikes could get all of them? That not a single one would survive to land on Seoul, Tokyo, or New York? Or that U.S. missile defenses would work betterthan designed, intercepting not most of the missiles aimed at the United States, but every last one of them? Are you willing to be your life on that?
On a good day, maybe we get most of the missiles. We save most of the cities, like Seoul and New York, but lose a few like Tokyo. Two out three ain’t bad, right?
I kid — but not really. Welcome to our new world. Don’t say I didn’t warn you.