The author is a historian who has published a book that is specifically about the history of nuclear secrecy in the United States. Not about the history of nuclear tech or nuclear weapons, about the history of restricted data, the special classification grade for the information. How the classification works and what is considered safe to release and what isn't is in itself one of his main research interests.

My impression from his book is that his position on nuclear secrecy is that a lot of it is pointless or outright contra-productive, but that isn't really the point of the blog post. The point of the blog post is that if something has changed about what information is considered safe to release, that is interesting to him. He is more interested in the humans and institutions than in the technology, I'd say.

> It is hard to understand what the author is hand-wringing about.

The issue seems to be “Organisations party to classified information have to keep it secret regardless of whether it’s in the public domain”.

As an academic historian the author is intrigued by the diagram - was it a mistake or was it authorised as a declassified representation? Either way, the consequences would be of interest.

> It is not that nobody knows how these weapons are supposed to work.

Optimally small, lightweight, robust, safe, reliable - all sorts of engineering short-cuts or novel techniques … you don’t want to give way accidental insights about the “hows” an enemy hasn’t thought of.

The "large industrial base" is required primarily to highly enrich uranium (or plutonium).

A modern fusion bomb requires much less of that than the initial fission bombs.

So I don't know how much a state actor could infer from an image like that, if we assume it's a schematic of an actual bomb.

But it's just not true that someone in possession of detailed plans for how to construct a bomb isn't put into a much better position. They'll need a much smaller amount of fissionable material than they otherwise would with a cruder design.