Jeffrey Lewis
@armscontrolwonk.bsky.social
Professor at the Middlebury Institute, member of the National Academies Committee on International Security and Arms Control, and former member of the State Department's International Security Advisory Board.
Getting ready for class on hypersonic missiles tomorrow.
November 10, 2025 at 2:35 AM
Getting ready for class on hypersonic missiles tomorrow.
Sadly, Erik did not take my art direction.
November 9, 2025 at 8:55 PM
Sadly, Erik did not take my art direction.
The conceptual definition was HE or 1 kilocalorie per gram.
November 4, 2025 at 12:59 AM
The conceptual definition was HE or 1 kilocalorie per gram.
All nuclear explosions are supercritical. He probably means “hydronuclear” — slightly supercritical with insignificant fission release (<1 lb). The US conducted ~35 during the 1958-1961 test moratorium. As a Harvard-educated lawyer, he can understand this—if it’s to his benefit.
November 4, 2025 at 12:42 AM
All nuclear explosions are supercritical. He probably means “hydronuclear” — slightly supercritical with insignificant fission release (<1 lb). The US conducted ~35 during the 1958-1961 test moratorium. As a Harvard-educated lawyer, he can understand this—if it’s to his benefit.
One thing I recently updated: US supercomputing zoomed past the benchmark established for stockpile stewardship (100 tflops) and also China has too. The Chinese have the computers to design new weapons, but what they don't have is the data from nuclear testing -- yet.
October 30, 2025 at 3:32 PM
One thing I recently updated: US supercomputing zoomed past the benchmark established for stockpile stewardship (100 tflops) and also China has too. The Chinese have the computers to design new weapons, but what they don't have is the data from nuclear testing -- yet.
Another resource: What would be the purpose of nuclear testing if the US matched what Russia is accused of doing? The @nationalacademies.org panel on the Comprehensive Nuclear Test Ban Treaty outlined what one might do with so-called hydronuclear, extremely low-yieldand very low-yield tests.
October 30, 2025 at 2:47 PM
Another resource: What would be the purpose of nuclear testing if the US matched what Russia is accused of doing? The @nationalacademies.org panel on the Comprehensive Nuclear Test Ban Treaty outlined what one might do with so-called hydronuclear, extremely low-yieldand very low-yield tests.
The @statedeptus.bsky.social 2021 "compliance report" is the most detailed unclassified statement on Russian, Chinese nuclear testing. DIA said something similar in 2019. Russia is directly accused of low-yield testing, while there are only concerns about Chinese transparency.
October 30, 2025 at 2:28 PM
The @statedeptus.bsky.social 2021 "compliance report" is the most detailed unclassified statement on Russian, Chinese nuclear testing. DIA said something similar in 2019. Russia is directly accused of low-yield testing, while there are only concerns about Chinese transparency.
It's normal to spiff up the capital when one takes power.
October 23, 2025 at 5:42 PM
It's normal to spiff up the capital when one takes power.
5 days ago, the ROK defense minister indicated North Korea might test the new large, solid-propellant ICBM that North Korea presented at its most recent parade (Hwasong-20). That's what we assume this is, although that's still speculation. No announcement by the Japanese yet.
October 21, 2025 at 11:59 PM
5 days ago, the ROK defense minister indicated North Korea might test the new large, solid-propellant ICBM that North Korea presented at its most recent parade (Hwasong-20). That's what we assume this is, although that's still speculation. No announcement by the Japanese yet.
Yes and yes. Look, I think everyone knows the rules are absurd, with the consequence that the powerful flout them because they can, while others must comply strictly. The rules should be fairly applied. I just tend to favor administrative punishments to criminal ones.
October 18, 2025 at 3:41 PM
Yes and yes. Look, I think everyone knows the rules are absurd, with the consequence that the powerful flout them because they can, while others must comply strictly. The rules should be fairly applied. I just tend to favor administrative punishments to criminal ones.
In 1971, Deputy Defense Secretary David Packard played a leading role in promoting the Safeguard ABM system—including plans for a massive underground nuclear test of the W-71 warhead beneath Amchitka Island, Alaska. The test was code-named CANNIKIN.
October 18, 2025 at 12:34 AM
In 1971, Deputy Defense Secretary David Packard played a leading role in promoting the Safeguard ABM system—including plans for a massive underground nuclear test of the W-71 warhead beneath Amchitka Island, Alaska. The test was code-named CANNIKIN.
With everyone talking about sea otters, Taylor Swift, and the Monterey Aquarium, I want to share some of @slair.bsky.social’s thesis research. Because before David Packard funded the rescue of sea otters at the Aquarium, he helped kill about a thousand of them in a nuclear test.
October 18, 2025 at 12:34 AM
With everyone talking about sea otters, Taylor Swift, and the Monterey Aquarium, I want to share some of @slair.bsky.social’s thesis research. Because before David Packard funded the rescue of sea otters at the Aquarium, he helped kill about a thousand of them in a nuclear test.
Excited to attend a @bulletinatomic.bsky.social & @stanfordcisac.bsky.social screening of A House of Dynamite.
October 15, 2025 at 2:07 AM
Excited to attend a @bulletinatomic.bsky.social & @stanfordcisac.bsky.social screening of A House of Dynamite.
I knew who you meant IMMEDIATELY.
October 13, 2025 at 10:31 PM
I knew who you meant IMMEDIATELY.
Soviet missileers.
October 13, 2025 at 9:18 PM
Soviet missileers.
Something happened during Kim Jong Un's visit to the new destroyer make Defense Minister No Kwang-chol (노광철) strip off his uniform. Maybe he was planning to shotgun a Taedonggang beer.
October 8, 2025 at 5:20 AM
Something happened during Kim Jong Un's visit to the new destroyer make Defense Minister No Kwang-chol (노광철) strip off his uniform. Maybe he was planning to shotgun a Taedonggang beer.
I am old enough to remember when very serious people™️ said we couldn't save money by putting the D5 in silos because it would require expensive new silos and other infrastructure.
September 29, 2025 at 7:28 PM
I am old enough to remember when very serious people™️ said we couldn't save money by putting the D5 in silos because it would require expensive new silos and other infrastructure.