James Acton
Co-director of the Nuclear Policy Program at the Carnegie Endowment For International Peace. I spend a lot of time thinking about nuclear weapons, advanced nonnuclear technology, and escalation.
- I'm thrilled to have a contract with @academic.oup.com for my book on "Entanglement and Unintended Escalation." (There'll be a better title!) The manuscript is drafted and currently being revised. Hopefully should be out second half of next year!
- Reposted by James ActonTesting nuclear weapons by detonating warheads is like “nuking yourself in the foot,” writes @nuclear-jim.bsky.social. Trump can stop nuclear anarchy by testing in ways that don’t spark a global arms race or give away the U.S.’s data advantage. More here: carnegieendowment.org/emissary/202...
- Let's not nuke ourselves in the foot! I explain why it's so difficult to know if China and Russia are conducting ultra-low yield tests and why, even if they are, it's not in U.S. interests to restart testing. @carnegieendowment.org @carnegienpp.bsky.social carnegieendowment.org/emissary/202...
- I am entirely indifferent whether, in the event of a nuclear war, I am incinerated by a nuclear warhead delivered by a "traditional" ICBM, a hypersonic glider, a nuclear-powered cruise missile, or a nuclear-powered torpedo. All seem equally suboptimal to me.
- ¯\_(ツ)_/¯
- The End of MAD? Join me, Steve Fetter, @jaysankarans.bsky.social, TD MacDonald, Ton Stefanik, @lauraegrego.bsky.social, @fiona-cunningham.bsky.social, and Charlie Glaser to discuss whether technological developments are undermining mutually assured destruction. Link for virtual rego in next post.
- Here's the link for rego: airtable.com/appGGluMUVck...
- The conference is based on a series of papers we published in the Journal of Strategic Studies. Many are open access (no paywall!). airtable.com/appGGluMUVck...
- Reposted by James ActonWhat exactly is the government hiding in Tucson? Not much, says @nuclear-jim.bsky.social. He got an interesting souvenir there, regardless. See the first installment of Carnegie Office Hours for more treasures from James (if not nuclear secrets) here: buff.ly/dlUzF6n
- I feel pretty strongly the @nytimes.com has the wrong framing here. This isn't serious; it's pathetic. I'd suggest something like: "Trump throws social media hissy fit invoking nukes after public spat with ex-president of Russia."
- We now go live to the Kremlin for Putin's reaction:
- As much as I deplore nuclear signaling by tweet--can't believe I just wrote that--I would NOT necessarily assume there's a been change to the US nuclear posture. The U.S. always keeps ~4/5 SSBNs at sea ready to fire.
- From Nuclear Notebook in @BulletinAtomic tandfonline.com/doi/figure/1...
- Ooops. Wrong handle: @scientistsorg.bsky.social
- Ahem (Deleted earlier version, which was missing caption!)
- Ah, yes, that crucial ninth significant figure...
- Good gracious, Ignatius! Why I disagree with the normally excellent David Ignatius; recent oped on Iran.
- Ignatius's oped is written as if it's a news story. The "news" in this case is that--SURPRISE!--an Israeli source backed up claims by the Israeli government! (3/n) x.com/james_acton3...
- The case for attacking Iran relied on emphasizing its technical prowess. The case that strikes were successful requires claiming that Iran is technically incompetent. foreignpolicy.com/2025/07/25/i...
- On Friday, I argued in @foreignpolicy.com that Trump admin claims it had set Iran back by "years" were true but disingenuous. The same day, the normally excellent David Ignatius amplified the misleading U.S. and Israeli narrative. www.washingtonpost.com/opinions/202... Let's take a look... (1/n)
- First off, here's the link to my @foreignpolicy.com piece. (2/n) foreignpolicy.com/2025/07/25/i...
- Ignatius's oped is written as if it's a news story. The "news" in this case is that--SURPRISE!--an Israeli source backed up claims by the Israeli government! (3/n) x.com/james_acton3...
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View full threadAnd, finally, given that hope is not a strategy, what's your plan to keep Iran in the NPT and to accept inspections--including of the 60% HEU that Israeli officials acknowledged survived the strikes. (12/12)
- 🎶When you attend a funeral, It is sad to think that sooner orl… …ater, those you love will do the same for you. And you may have found it tragic, Not to mention other adjec.. …tives to think of all the weeping they will do. 🎶 RIP, Mr Lehrer.
- Me in @foreignpolicy.com. The Trump administration's claim that Iran would need "years" to rebuild its previous nuclear program is like asserting that an unlocked bank vault would be impervious to a cyberattack. It’s true but misses the point. foreignpolicy.com/2025/07/25/i...
- Iran could build the bomb in a year or so without rebuilding its previous nuclear program. The loss of Iran's declared enrichment facilities and uranium metal production lines were simply not the crippling blows claimed by the Trump admin. (2/n) bsky.app/profile/nucl...
- 🧵How much damage was done to Iran's nuclear program? An analysis of Friday's reporting of the U.S. government assessment. I'll focus on the @nytimes.com, which was clearer than the earlier but confused @nbcnews.com story. (1/n) www.nytimes.com/2025/07/17/u...
- Claims/implications that Iran may struggle to recover the highly enriched uranium that is probably sitting underground at Esfahan are just silly. Digging debris out of tunnel entrances really isn't hard. (3/n) Spice warning:🌶️🌶️🌶️
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View full threadHere's the link to the whole thing again. Please take a read! (5/5) foreignpolicy.com/2025/07/25/i...
- Reposted by James Acton[Not loaded yet]
- 🧵How much damage was done to Iran's nuclear program? An analysis of Friday's reporting of the U.S. government assessment. I'll focus on the @nytimes.com, which was clearer than the earlier but confused @nbcnews.com story. (1/n) www.nytimes.com/2025/07/17/u...
- U.S. officials continue to argue that it would take Iran years to rebuild the facilities that were hit. That seems right to me. But a key question is this: How long would it take Iran to build the bomb? (2/n)
- Attempts to play down the survival of most or all of Iran's HEU are comical. It may be true that "only" the HEU at Isfahan is accessible--but that's almost all of it! (3/n)
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View full threadOne final point: Some folks will assume I'm making an argument for renewed military action. I'm not. My point is that there is no military solution. Even if the odds aren't good, diplomacy remains the option most likely to succeed in preventing Iran from proliferating. (12/12)
