> Being able to, as you put it, "generate several orders of magnitude" more energy will almost certainly result in new, better or more destructive weapon systems being devised.

We already use fusion technology in nukes. Hydrogen bombs work by using a fission reaction to start up an uncontrolled fusion reaction.

The hard part is controlling the fusion. So, I disagree - learning how to control fusion will not result in better weapons (at least, from a destruction standpoint).