Earlier quoted context omitted.
> Why go through the expense of... Good question. I should have asked strictly about fusion bombs. These being a known-working example of energy production by fusion, why not use them when we can't get 'controlled' fusion working?
Let me elaborate on thmsths's answer. The United States developed and tested large "clean" fusion bombs that produced only a very small fraction of their energy from fission. Those bombs could produce raw thermal energy at a cost below any fossil fuel or conventional nuclear reactor. For example, the Housatonic test shot of Operation Dominic in 1962 yielded about 10 megatons and 99.9% of the energy released came from…
Great answer, and from others too, thank you all.