As soon as Iran develops nuclear weaponry in quantity that is sufficient to deter any country from trying to attack it with nuclear weapons. That day will be the beginning of the end for the State of Israel and the West influence in the Middle East. The US, or NATO, or Israel can not face Iran in a conventional war fare with million man power unless Turkey is willing to sell its blood to the West.
Amnesty: Israel's 'Black Friday' Gaza strike a war crime (Haaretz)
from the article: Iran nuclear bomb could bring military balance of power, expert says