That's a ridiculous argument. By that benchmark any country has a responsibility to stop any other country's nuclear program because it is a potential threat to the world.
I feel like you wanted to reductio ad absurdum with a conclusion I feel is not absurd... um. It is staggeringly dangerous for anyone to have the tools to end civilization, because sometimes we lose track of things, and unless you're a comic book villain, destroying all human life within a multi-mile radius is not a super useful tool in wartime or peacetime.