Nuclear energy and Nuclear Fusion both are useful in creating major reactions. Thus, it only tracks that they’ll be useful for bombs and nuclear weapons overall. Of course, there is an issue with all of this. Once everyone knows about nuclear fusion and what it can do, nations will be able to develop their own weapons that they were once unable to do. This could speed up the production of nuclear weaponry, but some believe that fusion will actually cause nukes to essentially become obsolete. Everyone will be aware that nations have and can use a nuke, but no one will want to employ them due to the potential armageddon of it all. It is unclear whether or not the Nonproliferation Treaty (NPT) would account for nuclear fusion technology. Likely, it would not. So this will be a tricky international scenario to navigate.