The whole point of them is contradictory. IF they were a deterrent of war to promote peace (as many goverments keep purporting), we wouldn't have the constant fear of being wiped off the face of the Earth if someone decided to say "*Feck* you!" and send a few off, which would ultimately result in everyone else joining in and fecking everything up. While nuclear weapons were developed first and led to relatively good uses later (nuclear power, though that in itself is a bit iffy with all the radioactive waste, nuclear fallout through meltdowns, etc, etc...), they should never have been invented. Many of the scientists who developed them to end the WWII early were regretful of their decisions, so that clearly shows something is horribly wrong with something that has such power to end all life within a km radius in a second, not to mention everyone else effected by the radiation after. TLDR; You can't have peace when in constant fear. Nuclear Weapons are a no-no.