Matthew Bunn

@matthew-bunn.bsky.social

620 followers 140 following 400 posts

Father, husband, citizen, professor, focusing mainly on nuclear weapons and nuclear energy issues. Faculty lead for Harvard's Managing the Atom project: www.belfercenter.org/programs/managing-atom
My website: matthewbunn.scholars.harvard.edu .. more

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Matthew Bunn is an American nuclear and energy policy analyst, currently a professor of practice at the Harvard Kennedy School at Harvard University. He is the Co-principal Investigator for the Belfer Center's Project on Managing the Atom. .. more

Political science 44%

Engineering 24%

Posts Replies Media Videos

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Matthew Bunn @matthew-bunn.bsky.social · Oct 23

Proud to have been part of 50 years of work to reduce the danger of nuclear war at the Harvard Kennedy School, detailed in this new account in the Kennedy School's magazine. The effort is more urgent and essential than ever. www.hks.harvard.edu/faculty-rese...

Inside the Kennedy School’s long fight to prevent nuclear catastrophe

For generations, the insights and engagement of Harvard Kennedy School scholars have strengthened nuclear strategies and reduced dangers.

www.hks.harvard.edu

Matthew Bunn @matthew-bunn.bsky.social · 3h

ICYMI: NYT overview of the expiration of New START, with a brief quote from yours truly (and quotes from many others): www.nytimes.com/2026/02/05/u...

Nuclear Arms Control Era Comes to End Amid Global Rush for New Weapons

www.nytimes.com

Matthew Bunn @matthew-bunn.bsky.social · 21h

Boy, I wish I thought he was right about nothing stopping the march of truth…

Alex Wellerstein @wellerstein.bsky.social · 23h

"Truth is on the march and nothing will stop it. He who suffers for truth and justice becomes august and sacred. ...There is no justice but in truth; there is no happiness but in justice." – Émile Zola

Lyndon in front of a statue quoting the French writer Émile Zola, near the Zola metro station, Paris: "La verite est en marche et rien ne l’arretera. Qui souffre pour la verite et la justice devient auguste et sacre. ...Il n’est de justice que dans le verite il n’est bonheur que dans la justice."

Reposted by Matthew Bunn

Oliver Meier @olivermeier.bsky.social · 22h

"There is consensus among European countries that #NewSTART has worked in Europe’s favor. Russia’s war in Ukraine has deepened most European leaders’ preference to see continued commitment by US and Russia to limit nuclear deployments rather than no agreement, I told @cfr.org here:
is.gd/4Pf9WL

Europe Faces Uncertainty as New START Ends | Council on Foreign Relations

Confronted with the expiration of New START, Europe braces for a world without arms control. The loss of the traditional U.S. nuclear shield and Russia’s continued threats now force Europe to consider...

is.gd

Reposted by Matthew Bunn

Alex Wellerstein @wellerstein.bsky.social · 23h

Reposted by Matthew Bunn

Stephen Herzog @herzogsm.bsky.social · 2d

1/4

As the Trump administration’s “What about China?” nuclear arms control agenda for a New START follow-on unfolds, here’s a 2020 throwback. @thebulletin.org

Link here: doi.org/10.1080/0096...

Reposted by Stephen M. Walt

Matthew Bunn @matthew-bunn.bsky.social · 2d

Pete Hegseth's decision to end all military education and fellowships at Harvard is bad for the military, as well as bad for Harvard. I'm proud to say many of my former fellows are making big contributions to the U.S. military -- helped by their time at Harvard.

x.com

Matthew Bunn @matthew-bunn.bsky.social · 2d

Reply with actionable steps folks can take -- organizations to support, ways to volunteer, etc.

Matthew Bunn @matthew-bunn.bsky.social · 2d

It's all hands on deck for everyone who wants a free and fair 2026 election -- Ds, Rs, independents. We need to work together against all the means MAGA will use to tilt the scale. Useful David French piece on 2 important ideas -- but there are many more. www.nytimes.com/2026/02/05/o...

Opinion | A Law That Might Just Save the Midterms

www.nytimes.com

Matthew Bunn @matthew-bunn.bsky.social · 2d

Ankit Panda has a useful piece out on the accusation about Chinese nuclear testing. panda.substack.com/p/china-us-i...

China, U.S. Intelligence, and Nuclear Weapons Testing

Parsing out a new, specific U.S. claim.

panda.substack.com

Matthew Bunn @matthew-bunn.bsky.social · 2d

Of course, if the tests of concern are larger, that's another story. The NAS study provides a useful discussion of the potential value of tests of different sizes in Table 4-3. p. 116.

Reposted by Richard Weitz

Matthew Bunn @matthew-bunn.bsky.social · 2d

Full text: www.nationalacademies.org/publications...

The Comprehensive Nuclear Test Ban Treaty: Technical Issues for the United States 2012

This report reviews and updates the 2002 National Research Council report, Technical Issues Related to the Comprehensive Nuclear Test Ban Treaty (CTBT). T...

www.nationalacademies.org

Matthew Bunn @matthew-bunn.bsky.social · 2d

Re: US charges that China and Russia may have carried out very small "supercritical" nuclear tests, it's worth remembering that the 2012 NAS CTBT report said "we have
been unable to identify any significant advantage that could accrue to a State testing at these very low levels (<1 ton)." (p. 104)

Matthew Bunn @matthew-bunn.bsky.social · 2d

DiNanno's accusation that China violated the CTBT with a yield-producing test on June 22 of 2020 will be a headline from his remarks. If the evidence was clear-cut, the 4/25 compliance report presumably would have expressed more than vague "concerns" about whether Russia and China were complying.

Andrey Baklitskiy @baklitskiy.bsky.social · 3d

Pretty strong accusation against China on testing. Does this mean the US is now going to have a "yield producing nuclear test" (6 years later?)? Will the US release any supporting evidence?

Andrey Baklitskiy @baklitskiy.bsky.social · 3d

UnderSecT DiNanno: "China has used decoupling method to decrease the effectiveness of seismic monitoring to hide their activities from the world. China conducted one such yield producing nuclear tests on June 22 of 2020"

Matthew Bunn @matthew-bunn.bsky.social · 2d

With no limits, it appears that the United States and Russia will both begin increasing their force levels -- which may lead to even further Chinese expansion. Once those buildups are underway, it will be more difficult to reach deals to limit them.

Matthew Bunn @matthew-bunn.bsky.social · 2d

A "strategic pause" of a year or two or three would have offered time for talks, without interfering with long-term U.S. security options. thehill.com/opinion/nati...

thehill.com

Matthew Bunn @matthew-bunn.bsky.social · 2d

Rubio is wrong to say "the choice before the United States was to bind itself unilaterally or to recognize that a new era requires a new approach." The choice was whether BOTH Russia and the United States should stay within the limits while we explored options for new approaches.

Reposted by Richard Weitz

Matthew Bunn @matthew-bunn.bsky.social · 2d

Important statements on the Trump administration's arms control policy from Secretary Rubio and Undersecretary DiNanno, calling for future accords to include limits on both Russian and Chinese forces.
Rubio: statedept.substack.com/p/the-next-e...
DiNanno: www.state.gov/releases/202...

Statement to the Conference on Disarmament - United States Department of State

As Delivered Good morning colleagues. Thank you for hosting me today and for accommodating the schedule change. Thank you to Chargé Baasankhuu for Mongolia’s leadership of this year’s CD. Today marks ...

www.state.gov

Matthew Bunn @matthew-bunn.bsky.social · 3d

Brutal but accurate piece from George Will eviscerating Kristi Noem's "arbitrary, capricious, and lawless" attempt to revoke temporary protective status for essentially everyone who had it. A federal judge has blocked that attempt for now.

Opinion | A federal judge schools chaotic Kristi Noem

Blocking a government attempt to end temporary protected status for about 353,000 Haitians in the U.S.

www.washingtonpost.com

Reposted by Anna O. Law, Ben H. Ansell, Matthew Bunn , and 38 more Anna O. Law, Ben H. Ansell, Matthew Bunn, Dorothy Bishop, Steve Peers, Robert W. Wallace, Samuel L. Perry, Caroline Krafft, Jonathan M. Gilligan, Martin Paul Eve, Pierre Bataille, Lesley A. Hall, Peter Campbell, Calvin K. Lai, Peter Holmes, Peter Schöttler, Jonathan Hopkin, Robert C. Richards, Rebecca Tushnet, Alan Richardson, Silvia Secchi, Julia Lynch, Andrew L. Whitehead, Nazita Lajevardi, Stacy D. VanDeveer, Margot C. Finn, Stephen Jones, Jens Rydgren, Ben Rosamond, Dana R. Fisher, Cailin O’Connor, Lisa Diedrich, Paul Nightingale, Catherine J. Frieman, Gerardo Martí, Gayle Kaufman, Anthony Pecqueux, Olúfẹ́mi Táíwò, Marianne Blanchard, Nathan P. Kalmoe, Martin Winter

Victor Ray @victorerikray.bsky.social · 3d

I do want to shout-out my fellow sociologists, who have collectively created a discipline so woke that not a single one of our introductory textbooks can make it past Florida's censors.

Great work everyone.

The Board of Governors decided, unilaterally, that no published textbook in the field of sociology could be used in compliance with the law for an Intro to Sociology class. None.
Victor: There's not a single existing textbook on the market that could be used that would qualify under state law?
Zachary: Correct.
Victor: I'm sorry, that's kind of funny. Like, the absurdity of not a single sociology textbook getting past the censors. I mean, it makes me kind of proud of our colleagues, but...

Matthew Bunn @matthew-bunn.bsky.social · 3d

I would give the US a worse rating on “manipulating the law to stay in power,” though even more of that is coming as the midterms approach.

Robert N. Stavins @robertstavins.bsky.social · 3d

Read this and check out the index across all 12 dimensions www.nytimes.com/interactive/...

Opinion | ICE and Minnesota Have Pushed the U.S. Closer to Autocracy

Measuring America’s slide toward democratic erosion.

www.nytimes.com

Reposted by Stephen M. Walt, Matthew Bunn

Robert N. Stavins @robertstavins.bsky.social · 3d

Read this and check out the index across all 12 dimensions www.nytimes.com/interactive/...

Opinion | ICE and Minnesota Have Pushed the U.S. Closer to Autocracy

Measuring America’s slide toward democratic erosion.

www.nytimes.com

Reposted by Matthew Bunn

Andrey Baklitskiy @baklitskiy.bsky.social · 3d

Pretty strong accusation against China on testing. Does this mean the US is now going to have a "yield producing nuclear test" (6 years later?)? Will the US release any supporting evidence?

Andrey Baklitskiy @baklitskiy.bsky.social · 3d

Matthew Bunn @matthew-bunn.bsky.social · 3d

So, Axios reports a deal (in the works, not finalized) to stay within the New START limits for only six months (as in the 1st term, they somehow think this gives the US leverage), but Trump's post says don't extend, negotiate something better. Can we have some focused policy?

François Diaz-Maurin @francoisdm.bsky.social · 3d

Thanks, Mr. President.

We've got an editorial series of "expert comments" for you.

#NewSTART #armscontrol #nuclearweapons #nukesky

Reposted by Matthew Bunn

Jon B. Wolfsthal 🤯 @jonatomic.bsky.social · 3d

Thanka to Ian at Background Briefing for our useful discussion on Trump’s inexplicable decision to let New START nuclear agreement end with no replacement

www.backgroundbriefing.org

Background Briefing

www.backgroundbriefing.org

Reposted by Matthew Bunn

Nick Kodama @nickkodama.bsky.social · 3d

Nuclear possession is a fringe right wing nutjob position.

mainichi.jp/english/arti...

Q: Were there any candidates who thought that Japan should possess nuclear weapons?

A: A total of 24% of candidates standing for Sanseito answered that Japan "should possess nuclear weapons," as did 1% of candidates for the LDP and 2% for the JIP.

Reposted by Matthew Bunn

The Bulwark @thebulwark.com · 3d

"'The Framers of the Constitution understood that if the federal government were in charge of elections, that’s a path to tyranny.'"

Inside Dems’ Plans to Beat Back Trump’s Attacks on the Midterms

The party is taking concrete actions now to preempt the election meddling they know is coming.

lnk.thebulwark.com

Reposted by Matthew Bunn

Jon B. Wolfsthal 🤯 @jonatomic.bsky.social · 3d

It took Trump more time to post that he is letting New START die than it would have taken to extend it. But now Trump says he wants a new treaty, so here are ideas. I am skeptical he will follow up - we are still waiting for a North Korea deal and an Iran deal.

thebulletin.org/2025/09/why-...

The treaty limiting U.S. and Russian nuclear arms expired. What to know.

President Donald Trump said Thursday that he hoped to replace New START with a modernized treaty that could “last long into the future.”

wapo.st

Reposted by Matthew Bunn

Jenny Cohn @jennycohn.bsky.social · 3d

As I keep saying, MAGAs are promoting their “SAVE Act” as if their lives depend on passing it. Their promotion of SAVE is *everywhere* on X, but hardly anyone is warning what it really does or calling on voters to tell their Senators to vote NO. Tell your Senators to vote NO.

Reposted by Matthew Bunn

François Diaz-Maurin @francoisdm.bsky.social · 3d

Thanks, Mr. President.

We've got an editorial series of "expert comments" for you.

#NewSTART #armscontrol #nuclearweapons #nukesky

Reposted by Matthew Bunn

Just Security @justsecurity.org · 4d

“The nuclear non-profileration regime is in danger of collapse,” writes Kelsey Davenport.

Absent major shifts, countries like South Korea and Saudi Arabia may develop the technical means—and political motivation—to build a bomb:

www.justsecurity.org/129480/risk-...

In 2026, a Growing Risk of Nuclear Proliferation

In 2026, countries such as South Korea and Saudi Arabia will likely move closer to developing the technical means and political motivation to build a bomb.

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