1/7 How might AI enable the (non)proliferation of nuclear weapons? In a new #OpenAccess article in Risk Analysis (@socriskanalysis.bsky.social), Dave Allison & I explore this question. onlinelibrary.wiley.com/doi/10.1111/...

I'm happy to share that my second book, Wiring an Empire: Information Networks and U.S. Global Power in the Cold War, is under advance contract with MIT Press.

We have big plans @fpri.bsky.social and cannot wait to get started with our new distringuished fellow @armscontrolwonk.bsky.social and fellow @slair.bsky.social www.fpri.org/news/2025/09...

Wrote a Substack post about Iran's lackluster plan to rebuild its military after the 12-day war with Israel russiairan.substack.com/p/irans-plan...

New blog post up on Israeli & U.S. missile defense performance during True Promise II I broke up the defenses into midcourse and terminal phases, & looked at how well each performed Come for the effectiveness rates, stay for weird Arrow-3 launch buildings. www.armscontrolwonk.com/archive/1220...

Journalists: Please join us at the @outrider.org Nuclear Reporting Summit on October 9-10! This free, two-day event will focus on how #nuclearweapons issues intersect with AI, community health, #climatechange, local economies, and the #environment. 🔗 APPLY NOW: outrider.org/conference/2...

The Countdown to Prevent Another Iranian Nuclear Crisis Just Began My thoughts on snapback for @carnegieendowment.org carnegieendowment.org/emissary/202...

I wrote about Iran's missile failure rates during True Promise II Folks get caught up in the 50% failure rate figure from TP I and assume similar numbers are true for TP II and the 12 Day War. But, official statements and video evidence suggest its the failure rate is only 10%! Link below:

My colleague Seth Hosford and I wrote about Houthi SAMs. Turns out the Houthis are making jank thermal batteries to maintain their older SA-7b MANPADS, but the process behind it is wild! www.armscontrolwonk.com/archive/1220...

Y'all should check out my colleague Seth's ACW blog post on the Iskander-M ballistic missile! Turns out some of its maneuvers may be wholly random to bamboozle defenses www.armscontrolwonk.com/archive/1220...

A lot of technical assessments of Iran’s nuclear program feel rushed. There’s an overreliance on fuel cycle basics and projections built on major unknowns while overlooking domestic factors eg institutional disruption, procurement challenges, and acute paranoia.

MDA FY26 procurement requests: 🔶 37 THAADs 🔶12 SM-3 IIAs According to recent work by @slair.bsky.social the US Army might have used 39ish THAADs in defense of Israel. So this figure might count for the replacements and gives some credibility to Sam's figures.

Ooh, new document collection from @nsarchive.bsky.social (1400 documents on the DNSA database, but with free sample documents on the post) illuminates the history of U.S. nuclear nonproliferation policy between 1969 and 1977, including negotiations with Iran and intel on South Korea 🗃️

"It depends enormously on the type of rock."

Based on videos taken in Jordan, @slair.bsky.social was able to identify all of Israel's missile defense sites, determine the interceptor type based on their burn-time and then estimate the number of interceptors fired. A tour-de-force. www.armscontrolwonk.com/archive/1220...

It's really incredible how clearly one can make out the locations and interceptor types. The 39 THAAD rounds alone cost $495 million.

I've worked up an assessment of U.S. and Israeli missile defense interceptor expenditures since June 13 Based on video evidence AT LEAST, 39 THAAD, 34 Arrow-3, & ~9 Arrow-2s have been used. For more on the methodology, ABM sites in Israel, and implications, check out the article

For everyone being supremely confident that we can definitely detect and strike any future clandestine enrichment hall, let me remind you that North Korea built an entire enrichment cascade at Yongbyon and the IC completely missed it.

JCPOA > MOP

The Israelis finally hit the solid propellant production plant at Shahroud, but not as extensively as I would have expected A large casting building was destroyed, along with two high-bay buildings in one of the new solid propellant lines Thanks as always to our friends @planetlabs.bsky.social

Why am I so unimpressed by these strikes? Israel and the US have failed to target significant elements of Iran's nuclear materials and production infrastructure. RISING LION and MIDNIGHT HAMMER are tactically brilliant, but may turn out to be strategic failures. 🧵 1/17

Satellite imagery from our friends @planetlabs.bsky.social confirms the Israelis hit one of the missile bases near Shiraz the night of June 20-21. Support buildings and a missile checkout building were destroyed and started a fire. Possible damage to UGF entrances but its not clear. A🧵

Imagery of Natanz from this morning courtesy of Airbus shows the crater left by Massive Ordinance Penetrators (MOPs) over the underground enrichment halls While there was discussion over whether the centrifuges had been damaged by the Israeli strikes, they're almost certainly damaged now.

New imagery of Isfahan from this morning courtesy of Airbus shows the damage from U.S. Tomahawk strikes The strike focused on the uranium conversion plant, hitting buildings undamaged or partially damaged by past Israeli strikes

Lots of the damage to the fuel plate/zirconium plant on the north side was done the night of June 20-21 by the Israelis. Our friends @planetlabs.bsky.social captured the damage in their daily 3m

Remember Decker's golden rule: when crisis starts, instead of immediately posting stream of consciousness, stand up, pour yourself a strong drink, and do something else. The takes can wait an hour or two.

If Iran potentially having 8,000 missiles in five years was truly one of the main reasons why Israel decided they had to strike now, that is not a great endorsement of missile defense being deescalatory. Instead we see a missile arms race leading directly to war.

In the words of the Blessed Saint, Thomas Crombie Schelling: "Most of what we call civilization depends on reciprocal vulnerability."

We can now see the damage from Israeli strikes on the missile bases in Isfahan thanks to the daily 3m images from our friends @planetlabs.bsky.social All the missile checkout buildings were destroyed at the Isfahan north base, likely hampering Iran's ability to generate strikes from there

If the administration wants to join the attack against Iran, it should make its case to Congress and request an AUMF. There is no imminent threat of the kind that would justify bypassing Congress.

Imagery of the Tabriz North missile base from today courtesy of our friends @planetlabs.bsky.social shows the extent of the damage from the Israeli strikes Two UGF entrances were damaged or sealed while another two remained open. Many missile checkout and support buildings were destroyed

ICAN estimates that global nuclear weapon spending in 2024 amounts to $100 billion. However, the actual worldwide expenditure on nuclear weapons is likely even higher, perhaps as high as $150 billion. This is because spending in Russia and China is likely significantly higher. 📈 Here is why. 🧵 1/

We can see damage to many buildings at the Uranium Conversion Facility and some smoke from fires, but no obvious damage to the FPEP in the imagery so far. Thanks to our friends @planetlabs.bsky.social for the images

Geolocation of missile strike in Tel Aviv near the Magalit Tower. 32.074265°, 34.786614°

Got the first look at the Tabriz North missile base, thanks to our friends @planetlabs.bsky.social Definitely some damage visible in the 3m, maybe some near the tunnel entrances as well

We have a look at the damage at Kermanshah missile base thanks to our friends @planetlabs.bsky.social

Satellite images of Natanz and Fordow this morning from Airbus that @armscontrolwonk.bsky.social and I looked at All the damage to Natanz is at the original complex. Electrical infrastructure was targeted, along with the Pilot Fuel Enrichment Plant. The UGF entrances were not damaged

Feeling pretty vindicated about the work on Iranian air defenses that @armscontrolwonk.bsky.social and I did a month ago breakingdefense.com/2025/05/iran...

Iran announces it has launched Operation True Promise 3. 50/

A note on this: Israel is calling this operation a "preemptive" one; this is incorrect. It is preventive (which is illegal under international law). Netanyahu himself suggested Iran was "months" to "a year" away from a nuclear weapon capability in his speech announcing the operation.

Possible debris from today's strikes. Looks like an Israeli air-launched ballistic missile, either a Sparrow or a ROCKS.

Fires at Natanz Uranium Enrichment Plant based on video geolocated to the road outside the facility: 33.738 N°, 51.737 E° @armscontrolwonk.bsky.social and I have been talking about the vulnerability of air defenses there a lot the past few weeks

“Iran has 2,000 ballistic missiles with warheads that can carry 2,000 pounds of explosives or more…since the previous Iranian missile strike on Israel, in Oct. 2024, Iran has significantly increased production of ballistic missiles to around 50 per month” www.axios.com/2025/06/12/i...

Looks like Israel has struck Iran. It's going to be a long evening.

Timelapse of the past year at the underground facility near Natanz which may be the third enrichment facility the Iranians announced earlier today. Growing spoil piles suggesting continued excavation and lots of work on the perimeter. Thanks to our friends @planetlabs.bsky.social

Iran has been months away from a nuclear weapon since ~2007. Whatever holds Khamenei back is political, not technical. Politics are worth keeping in mind because (1) some Iranians still oppose a bomb and (2) bombing them will settle that argument in favor of the other Iranians.

Apparently this needs to be said. Iran was complying with the JCPOA until Trump abandoned it. Iran was complying with the JCPOA until Trump abandoned it. Iran was complying with the JCPOA until Trump abandoned it. Iran was complying with the JCPOA until Trump abandoned it.

Washington Post: The U.S. is on high alert in anticipation of a potential Israeli strike on Iran www.washingtonpost.com/national-sec...

This is probably the the new North Korean uranium enrichment facility that @iaeaorg.bsky.social DG Grossi briefed the Board of Governors about. @slair.bsky.social and I have a summary on the blog. Nice shot by our friends at @planetlabs.bsky.social BTW.

Consistent with Kim Jong Un's stated goals to size up his nuclear forces. Good work here.