WW3 can wipe out every living hings from the face of earth, there are many nucelear weapons that can have this devastating and catastrophic effects, people need to start living and accepting each other to move forward as species, if unity cannot be formed it is only a hindrance for us as human kind and we will be made extinct by our own actions, live and let live.
Thankfully, there are at least half a dozen nations, which are having nuclear weapons right now. If only one of the countries were having this capability, then there was a chance of that nation nuking some other less powerful nation (just like the US nuked Japan in 1945). But the fear of a retaliation in the same kind will keep the nuclear weapon-armed nations to exercise restraint.