I dunno. If Japan were willing to throw in their influence, it might go somewhere. It's kind of hard to argue with the only people in the world who have directly suffered the effects of nuclear war.
That's a rather big "if", of course - the Japanese government's not very keen on upsetting the US, Russia, or North Korea.
Still, it's kind of bizarre, isn't it? Why exactly do the nuclear powers still need thousands and thousands of warheads? Surely scant dozens would be more than "enough"?