This morning in North Korea, last night here, North Korea tested another nuclear device underground at its test site. The yield appears to be larger than the last test, but determining that depends on how deep the test was and other factors that we don’t know. US planes are flying in the area to collect isotopes that may have been released in the test, but the North Koreans have been very skilled at containing their tests, so that may not give much information.
For the last two North Korean tests (five total), a lot of discussion takes place on Twitter, among experts in Seoul, Vienna, Washington, Monterey (CA), New Mexico, and other places. A good list of people to follow is here:
My impression so far: This is the latest in a series of tests in which the North Koreans are dealing with particular design features, probably only a few. It’s not possible to say what they are from the very little information we have from the tests. The North Korean statement says that the design is ready to be mated to the missiles they’ve been testing and they can produce the warheads in numbers. North Korea tends to exaggerate, but it is clear that that is their goal.
We need to engage the North Koreans in discussions. In the past, they have slowed their progress toward nuclear weapons when they have been in negotiations. They are making progress toward weapons that can be used against South Korea and Japan. With more work, they will be able to reach the United States.
Plain talk from Jeffrey Lewis. And as far as I can see, he’s right.
More from Jeffrey. He spins a mean worst-case scenario.
I found this while answering a question on Twitter: How the Soviets did their underground nuclear tests. Chapter 2 explains in detail how nuclear tests are contained, with helpful diagrams. ALso a reminder of how the US and Russia worked together after the fall of the Soviet Union.
Photo of Kim Jong Un inspecting their claimed nuclear device from earlier this year.