The degree of polarization that currently exists in Washington is such where I think it's fair to say if I presented a cure for cancer, getting legislation passed to move that forward would be a nail-biter.

Ultimately, I remain optimistic about not just America's future, but the direction that the world is growing.

In a summer marked by instability in the Middle East and Eastern Europe, I know the world also took notice of the small American city of Ferguson, Missouri - where a young man was killed, and a community was divided. So yes, we have our own racial and ethnic tensions.

Al Qaeda, the Taliban, a whole host of networks that are bent on attacking America, who have a distorted ideology, who have perverted the faith of Islam, and so we have to go after them.

I think there are a lot of factors going into an election. I think the bottom line is - is that Donald Trump is gonna be sworn in as the 45th President of the United States of America. And it's not necessarily profitable to sort of try to untangle all the different factors that went into it.

There are things I cannot say.

Over more than a decade, Iran had moved ahead with its nuclear program. And before the deal, it had installed nearly 20,000 centrifuges that could enrich uranium for a nuclear bomb.