See above. Don’t become a munitions engineer, and, being aware that someone else will take that role, try to prevent anyone from taking that role. (Hint: That last part is very hard.)
The conclusions might change if planet-destroying bombs are necessary for some good reason, or if you have the option of safely leaving the planet and making sure nobody that comes with you will also want to build planet-destroying bombs. (Hint: That last part is still hard.)
What if it is a bomb so big that it will destroy the entire planet?
See above. Don’t become a munitions engineer, and, being aware that someone else will take that role, try to prevent anyone from taking that role. (Hint: That last part is very hard.)
The conclusions might change if planet-destroying bombs are necessary for some good reason, or if you have the option of safely leaving the planet and making sure nobody that comes with you will also want to build planet-destroying bombs. (Hint: That last part is still hard.)