Iran has essentially mastered all of the complex science and technology that they need to have a completely indigenous nuclear weapons program. That means that our options on Iran are extremely limited, to regime change or as a last resort, the use of force.

A lot of people have said to me, 'That's a great idea, running for president. You'll get booked for more speeches. You can write a book.'

You have to negotiate from positions of strength. And right now with Iran, we're not negotiating from a position of strength. The Europeans are negotiating from the position of "Please give up your nuclear weapons program, and by the way if you do we'll give you several boatloads of carrots." The Iranians are quite willing to keep on negotiating on that line for a long time.

Don't get me wrong: I would love to be president.

Let me ask, who died and made him king? Who gave him the authority to endanger 300 million Americans? That's not the way it works, and if he thinks he can get away with that, he's got another think coming.

I'm not saying that you need a State Department that looks like the litigation department of a major law firm. But you need people who are not afraid to make the case for the United States, who are not afraid to stand their ground, not afraid to be isolated in international organizations when that's the correct approach for our diplomacy. This is a cultural change that has to be effected through incentive systems, promotion systems, career training systems. This is not something that you can do with the stroke of a magic wand, it's going to take years to make this change.

I think the regime in North Korea is more fragile than people think. The country's economic system remains desperate, and one thing that could happen for example would be under a new government in South Korea, to get the South Korean government to live up to its own constitution, which says any Korean who makes it to South Korea, is a Korean citizen. A citizen of the Republic of Korea. And you could imagine the impact that would have inside North Korea if people thought, "If I could get out and make it to South Korea, I could have a different life."