>>12458574They can't handle fusion to use for energy so they can only use it in weapons, because in order to make the hydrogen combine into helium it needs to be really hot, like as hot as the sun, hotter even for their purposes, so nuclear fusion (hydrogen > helium) is not used for energy harvesting because it is impossible right now it would melt the facility you do it in, it can only be used for bombs right now.
"Cold fusion" is the idea of using fusion for energy harvesting but right now it is too hard to do so they don't do it because they don't know how to yet.
Basically, plutonium and uranium in atom bombs work by splitting the atoms into smaller atoms like iron, by causing a chain reaction that breaks the atoms into pieces, and when the atoms break into pieces, the waste products combined result in a lot of energy being released which is the atom bomb.
That fission bomb in turn sets off the fusion chamber which is a second bomb that literally needs another bomb just to turn it on. The fusion chamber combines atoms, the hydrogen will naturally combine on its own to form helium but it needs to be really hot to do this, so that is why they use a bomb to set off this other bomb.
That is how modern nukes work.
