When that book came out, I cringed a bit; thought that he had quoted a bit too much of Ted Taylor's lore: recall when he discussed a 'problem' of yield (I forget the context now - but it was about early fission tests or transitional to the 'Mike' kluge which.. nevertheless vaporized Elugelap atoll). Gotta hunt up my copy..
He said.. ~ "if you were going to drive a nail, you wouldn't put the head up to it and push, would you?" Innocent enough, but it referred to a (then) pretty clever idea and - it sure as hell wasn't declassified. Of course, now we have Chuck Hansen's book with *pictures* and much of the substance of any mysteries diagrammed (!) even on to rudimentary thermonuclear tricks, including doping, reflectors, Po-Be n source, F-F-F: the works.
What has declined however, in this vaunted US amateur experimentation - is the art + science too: represented by the Heathkit Co. No more kits from there; few left who use a soldering iron and merely construct (a TV, say - more than a few housewives did exactly that! once). All their excellent manuals gave both an overview explanation and then a detailed one of the exact operation of all the stages. Their test equipment wasn't quite HP in precision of pieces or accuracy, but - it was exc. training and explanation better than most texts. Many later engrs -- became interested via Heathkits, as kids.
(I still use one of Heath's later and superb designs - which produces a rise-time of ~600 pSec - for scope risetime measurement and adjustment; it exceeds the performance of a couple $1500 "trade" devices of a decade ago and is equiv. quality to HP of a few years earlier. Ditto their tiny Geiger counter which was a kit form of the Monitor 4 and able to read alphas as well as very lo-energy X-rays. Lab quality. Alas, they made things like this just before they had to fold - for lack of interest.)
Today we mainly buy stuff assembled (as always was cheaper - if labor is paid or figured-in). Even Hams / radio amateurs now most-often buy; they do not build. (Most that is; there's always a creative group at the core).
It is apparent that fewer and fewer (old or young) today know even Ohm's Law: this while more and more of the environment is not merely electical but electronic in operation! So I don't know if Doug's comments apply as much as they once did {??} nor then, is the barrier to parity of the Chinese so unthinkable..
Ashton
(And yes IMhO there are entirely too many people who know how to make a crude fission device -- while there are kilotons of Pu everywhere: at least that demands an implosion device; U235 makes the task almost too trivial to think about for long, in a world of loonies and some of those now in charge Here. All U235 ought to be guarded IN Fort Knox IMO)