In the case of nuclear weapons, the knowledge of the science of how they work is not sufficient. The "industrial arts" of making fissionable material and then w

In the case of nuclear weapons, the knowledge of the science of how they work is not sufficient. The "industrial arts" of making fissionable material and then weapons are complex, expensive, and large scale. Just knowing the science doesn't mean that you are able to design, build, and operate the factories that are needed for production. On the other hand, any technology which depends only on fairly standard scientific instruments, readily available components and manufacturing techniques, and software is essentially uncontrollable.