happy_Alex said:Do the current nations with nuclear weapons have any moral right or justification to stop other nations from developing them?
It's more pragmatic than anything else. "We know we won't blow up the world but we aren't so sure about these other guys." Also pragmatic from the sense that we can't dictate the nuclear progress of larger countries like China and Russia as someone else noted. The world isn't a perfect place and there are no hard and fast rules to international politics.