I would trust Israel, the US, Great Britain, even France and China with nuclear weapons much more than I would trust Iran, Libya, Syria, Egypt, Indonesia and a few other of those islamic and non-islamic dictatorships.
Hard to trust Pakistan and India too much, but what can you do right now.
I doubt that Iran will get away with their sleight of hand in any case, so it is a fairly wasted discussion. US will never allow it as it will change the balance of power in too many ways that are not to the advantage of the western world.
Of course I would agree that this would be a sensible position to side with.
Nuclear weapons are a fact of life, not going away any time soon, so better the side that I consider to be the more sensible and reliable be the only one to have them, and I hope that they remain sensible enough to ensure that they are the only ones to have them.
