It's much easier to make a fission reactor than a fission bomb, and much easier to make a fusion bomb than a fusion reaction. They are not even that similar.
It's way easier to make a fission bomb than a fission reactor. I reactor has to stay in the very narrow window where it's critical but not prompt critical. Even pure fission bombs can be marvels of engineering but the simplest gun-type bomb is easier to build than the simplest nuclear reactor.
It's much easier to make a fission reactor than a fission bomb, and much easier to make a fusion bomb than a fusion reaction. They are not even that similar.
It's way easier to make a fission bomb than a fission reactor. I reactor has to stay in the very narrow window where it's critical but not prompt critical. Even pure fission bombs can be marvels of engineering but the simplest gun-type bomb is easier to build than the simplest nuclear reactor.