Heavy damage may call for a nuclear response in order to stop it. You know, much as the US did to stop WW2. The consequences have to be so unbearable to Iran that they will cease and desist. Iran is also a threat to Saudi Arabia and other countries in the Middle East. The biggest threat to World Peace are those who seek to appease Iran. Appeasement never got anywhere but war. Looking back over 5 thousand years has there ever been world peace? It is a myth. Only the strong survive.
Iraqi: Government forces have regained full control of Ramadi from ISIS (AP)
from the article: Iran military head warns of 'heavy damage' should Israel attack