General [James] Mattis has said that the deal's in place. We can't unilaterally pull out of it without support from our allies because the sanctions wouldn't bite as deeply. And so he'll find other ways to push back against Iran in the various conflicts that Iran is fomenting around the [Iran] region.

Why do soldiers fight? They join because they believe in a higher cause -- protecting religion, their nation, defending against a foreign nation. But why do soldier stay and fight? Soldiers aren't individuals. They are part of a unit. And that unit is led by a commander. If they don't trust their commander ... if there is no leadership, there is nothing.

Iran has proxies in Yemen, Syria, Iraq. You can push back against Iran without pulling out of the deal.

[General James Mattis] said, reading allows you to learn from other people's mistakes without filling body bags with the bodies of your soldiers as you learn on the battlefield.

I think that you will see some significant changes in the [Donald] Trump administration.

t I think what [James Mattis] will do with the deal is monitor it very, very carefully and make sure that Iran is complying with every stipulation of it.

Certainly, we shouldn't go about making a habit of taking generals and making them secretary of defense.