In an interview given by Panetta and the chairman of the Joint Chiefs of Staff General Martin Dempsey to CBS News, Panetta made it clear that "our red line to Iran is to not develop a nuclear weapon. That's a red line for us."
General Martin Dempsey tried to avoid answering how hard it would be for the US to take out Iran's nuclear capability but eventually answered, saying: "I'd rather not discuss the degree of difficulty and in any way encourage them to read anything into that."
"But I will say that -- our -- my responsibility is to encourage the right degree of planning to understand the risks associated with any kind of military option... in some cases to position assets, to provide those options... in a timely fashion. And all those activities are going on."
When pressed whether the US could "take out their nuclear capability" without using nuclear weapons, Dempsey said this: "I certainly want them to believe that that's the case."
Panetta added: "I think they need to know that... if they take that step - that they're going to get stopped."
Dempsey also declared that while the Iranians have the capability to block the Hormuz Straits for a time, the US would also be able to "defeat" them if it happened.
As for the possibility of an Israeli strike against Iran and the US' response to such a strike, Panetta said the US would protect its forces in the region.
"If the Israelis made that decision, we would have to be prepared to protect our forces in that situation. And that's what we'd be concerned about."
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