The city of Kyoto was the only great city of Japan to be spared serious bombing during World War II, despite being among the top targets preferred for the atomic bomb, thanks to the unprecedented and extraordinary efforts by the Secretary of War, Henry L. Stimson, to protect it. I have written at length on this, and why I have come to think that the issue of Kyoto is actually the key to understanding quite a lot about Truman and the bomb, both prior to and after its use. Whenever the issue of Kyoto comes up in popular discussions, however, one other assertion always arises: that Stimson saved ..read more

When I learned several months ago that Daniel Ellsberg had pancreatic cancer, and was opting not to treat it, I was not quite sure what I ought to do. I consider it a great honor that I got to spend several days with Ellsberg, a few years back, and was periodically in touch with him since then. I’d like to think he was something of a friend, though I never knew him deeply or for that long of a time. After thinking on it for several days, and feeling conflicted, and talking about it with a friend whose life experience exceeds mine by almost five decades, I opted not to reach out to him when I h ..read more

One of the sleeper news items of last week was that the Department of Energy officially vacated the Atomic Energy Commission decision that stripped J. Robert Oppenheimer of his security clearance in 1954. It did come as a surprise to me. I knew that there was a campaign to overturn Oppenheimer’s clearance loss — I had been asked to give representatives from the American Institute of Physics a background talk about it, in order to help them determine whether to take a stance on it — and also knew that there had been previous, unsuccessful efforts in this respect. “Beyond loyalty, the harsh req ..read more

This is second post of a two part series on this topic. Click here for part one. Did the Japanese offer to surrender before the atomic bombs were dropped in August 1945? In my first post earlier this week, I gave what we might call the standard diplomatic history answer: no, they didn’t. There were “peace feelers” to the Soviet Union from an important minority of the Japanese government, which is quite interesting and complicates the overly-simple picture of Japanese fanaticism that is often told about their refusal to surrender, but they don’t constitute, in any meaningful sense, a real offer ..read more

This is part one of a series of two posts on this topic. The second post will be posted later this week. One of the most common invocations made in the service of “the atomic bombs weren’t necessary” argument is that the Japanese offered to surrender well before Hiroshima, and that this was ignored by the United States because they wanted to drop the bombs anyway (for various other asserted reasons). It’s one of those things that has a grain of truth to it, but without a heaping of context and interpretation is misleading by itself.  The Suzuki Cabinet, who held the fate of Japan in thei ..read more

In early February 2022, as readers will have seen, I celebrated the tenth anniversary of the NUKEMAP. Privately, I had been reflecting personally on how the usage stats had been lower since the end of the Trump presidency. My feelings about the NUKEMAP usage stats are always a bit conflicted, since usage patterns tend to be lower when people are less worried about nuclear detonations, and while I do think people should be in general more worried about nuclear detonations during non-crisis periods than they are (because the possibility is still there), I don’t desire crisis periods. I’ll admit ..read more

A quick note: Because of the war in Ukraine and Putin’s mention of nuclear weapons, NUKEMAP has been for the last week experiencing abnormally high loads of traffic. This has meant that a lot of people are having trouble accessing the website. I’ve been doing what I can to help on the back end of it, but there are limits to my resources and knowledge about such things. In the meantime, I have created a temporary, authorized mirror of the website that you can try to use: https://nukemap.org/nukemap/ (If you are wondering, “why does the blog work when NUKEMAP doesn’t,” it is because they are on ..read more

I was somewhat surprised to realize that today is the 10th anniversary of my unveiling of NUKEMAP. Historians should not be surprised by the passing of time, but people are, and historians are people, so, well, here I am, continually surprised. NUKEMAP as it looks at the moment. You can see some previous iterations in this post. The most disturbing effect of the passing of time with NUKEMAP has been the slightly different ways in which people talk to me about having used it. After a couple of years, I started to get people coming up to me and saying, “I used NUKEMAP when I was an undergradua ..read more

In my recent article on the occasion of the 60th anniversary of the Tsar Bomba test, I relied very heavily on Russian sources that were digitized by Rosatom, the Russian nuclear agency. For whatever reason, Rosatom has been dedicating an impressive amount of resources to Soviet nuclear history, radically transforming what is easily available to scholars outside of Russia. The extraordinarily useful series of (curated, redacted) archival documents, Atomniy Projekt SSSR (Atomic Project of the Soviet Union), for example, went nearly overnight from being something only existed in full in a ha ..read more

The Q Clearance is the enigmatically-named security clearance created to allow access Restricted Data, the legal category for nuclear secrets in the United States (after which my book is named). It is issued by the the US Department of Energy, and requires a single-scope background investigation (originally by the FBI), with the same requirements as a Top Secret clearance, and keeping it requires being re-investigated every 5 years.  A Restricted Data stamp from a document from the 1940s. If you don’t have a Q Clearance, you’re not supposed to see things like this. Don’t worry, this one ..read more