people, people!
The nuclear arsenal is not something that will destroy us. It's something that keeps strongest nations away from a new world war! Most of high military commanders in all the strongest countries are, I'm pretty sure, with higher intellect that an average hiver. So, they do realise that whenever they begin a war, everyone will be destroyed and there will be no winners. If there would be no nukes, they fouldn't be scared that country they attack would nuke them, forcing them to nukes, releasing all the arsenal of their and destroying half of earh population...