"I want the Iranians to know that if I'm the president, we will attack Iran (if it attacks Israel)," Clinton said in an interview on ABC's "Good Morning America."

"In the next 10 years, during which they might foolishly consider launching an attack on Israel, we would be able to totally obliterate them," she said.

We must ensure that lawless states and terrorists will not be armed with weapons of mass destruction.

This is the single gravest threat to our security. Any potential adversary should know that we will defend ourselves against the possibility of attack by unconventional arms. If such a strike does occur, as commander-in-chief, I will respond with overwhelming and devastating force. If such an attack appears imminent, as commander-in-chief, I will do whatever is necessary to stop it. And, as commander-in-chief, I will never cede our security to anyone. I will always do what is necessary to safeguard our country.