What Israel and US are really afraid of, is that once Iran acquires a functional nuclear capability, they will no longer be vulnerable to invasion and control by US/Israel. But the threat of invasion or bombing of Iran is necessary for the US to maintain its control in the Middle East and the stable flow of oil. Yet, it's precisely these threats that have induced the Iranian regime to pursue the membership in the nuclear weapons club.
15 police officers killed in Colombia helicopter crash (Reuters)
from the article: Iran is too rational to attack Israel