James Acton

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!

Trump Has an Out on Nuclear Testing. He Should Take It. Sometimes good policy can be as simple as not nuking yourself in the foot.

Testing 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...

Trump Has an Out on Nuclear Testing. He Should Take It. Sometimes good policy can be as simple as not nuking yourself in the foot.

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...

elmo from sesame street standing in front of a wall ALT: elmo from sesame street standing in front of a wall

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)_/¯

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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...

Airtable | Everyone's app platform Airtable is a low-code platform for building collaborative apps. Customize your workflow, collaborate, and achieve ambitious outcomes. Get started for free.

Here's the link for rego: airtable.com/appGGluMUVck...

a man in a shirt and tie is screaming with his hands in the air . ALT: a man in a shirt and tie is screaming with his hands in the air .

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.

What 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

Yes, absolutely.

a man in a suit and tie is smiling while sitting at a table with his hands folded . ALT: a man in a suit and tie is smiling while sitting at a table with his hands folded .

We now go live to the Kremlin for Putin's reaction:

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."

Ooops. Wrong handle: @scientistsorg.bsky.social

From Nuclear Notebook in
@BulletinAtomic

tandfonline.com/doi/figure/1...

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.

Success Academy’s Radical Educational Experiment Inside Eva Moskowitz’s quest to combine rigid discipline with a progressive curriculum.

From @newyorker.com

www.newyorker.com/magazine/201...

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.

There’s More Than One Way to Build a Bomb Iran doesn’t need to rebuild its damaged facilities to sprint for a nuclear weapon.

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...

And, 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)

Given the U.S. developed the uranium metal production process in the 1940s in a university lab with equipment from the 1920s, why do you suppose Iran will struggle to replicate the process outside of Isfahan? (11/n)

The U.S. did not even try to collapse the very deep tunnels at Isfahan where most of Iran's HEU was stored. Are you concerned that, in reality, the United States has clearly signaled the limits of ability to destroy underground facilities with nonnuclear weapons? (10/n)

What's Israel's plan for dealing with the HEU that Israeli officials acknowledge survived the attack?

Does Israel know the location of Iran's stockpile of centrifuge components, which have not been under monitoring since 2021 following the Iran Deal's collapse? (9/n)

To close, some questions for Ignatius' source.

What happens if "activities" are being conducted too far underground for Israel to destroy? Do you expect the U.S. to attack again? If yes, what happens if the activities are too deep for the U.S. to reach? (8/n)

Finally re timeframe, as Eric has observed, the claim that Iran is 1-2 years from the bomb is actually similar to pre-war estimates, including from NETANYAHU himself. (7/n)

Ignatius is also inconsistent. Back in 2015, while generally supportive of the Iran Deal, he argued its 10-year timeframe (again, misleading) meant Obama was making a "big bet."

Now, an attack with much shorter-term effects is a success. (6/n)

washingtonpost.com/opinions/aft...

Moreover, both Netanyahu and Ignatius are being inconsistent in defining success.

Netanyahu attacked the Iran Deal on the misleading grounds that its limits only lasted 10 years. Now Israel is claiming a 1-2 year delay is a success. (5/n)

bsky.app/profile/nucl...

U.S. scrambles to determine impact of strikes on Iran’s nuclear sites Trump says Iran’s nuclear program was obliterated, but questions remain about Iran’s capability and the location of hundreds of pounds of highly enriched uranium.

In fact, the source is actually walking back earlier Israeli claims!

Previously, Netanyahu said Iran's program had been set back 2-3 years. Now Israel is saying 1-2 years. (4/n)

washingtonpost.com/national-sec...

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...