Assuming Yadlin is right then Netanyahu's credibility is more on the line than over anything else. He said "We will never accept a nuclear Iran". It won't be sufficient an excuse to say that US would not agree to our taking military action...even if it was to protect our existence.
Israeli justice minister: Pollard will be released November 20 (Haaretz)
from the article: MI chief: Iran has enough nuclear material for bomb