are precisely zero. While I strongly prefer that Iran did not have nukes; the only plausible way I see to stop them is for Israel to abandon its nukes; and have that being verified. That alone would probably lead to Iran abandoning its plans; but if not, I believe the world would then and only then back very tough sanctions.
UN to hold off on separate Afghan bombing probe for now (Reuters)
from the article: China rejects Iran sanctions, pushes for diplomatic solution