My understanding is that "hot" fusion is actually fairly easy - it's generating a surplus of energy from fusion[*] outside of a nuclear weapon that is the tricky part.
[Note: Typically in most H-bomb designs most of the energy still comes from fission - the fast neutrons from the fusion in the secondary igniting fission of the DU tamper round the secondary].
> My understanding is that "hot" fusion is actually fairly easy ...
Unless you're talking about a thermonuclear weapon, it's not easy at all. In fact, decades of research have yet to produce a break-even reaction in the laboratory.
http://en.wikipedia.org/wiki/Fusor
[Note: Typically in most H-bomb designs most of the energy still comes from fission - the fast neutrons from the fusion in the secondary igniting fission of the DU tamper round the secondary].