I believe it is highly likely that the further development of nuclear weapons will more than likely be the beginning and main topic of a future world war. History has showed us that war can cause governments and people in power to do strange things. I believe we are capable of ruining our own planet.
No, development of nuclear weapons will not fuel a third world war, because we all know of what the other countries are capable of. Any country that dares use a nuclear weapon knows that it will likely receive one in return. It has actually done a good job keeping the world's wars at bay.