One of the toughest battles in intelligence is combating conventional wisdom.

I have tried to maintain civil relationships with everyone I meet - and, even if I violently disagree with them, try to be respectful.

I will always be an advocate in terms of wars of necessity. I am just much more cautious on wars of choice.

There will be boots on the ground if there's to be any hope of success in the strategy.

It's clear the relationship between China and North Korea has hardly ever been worse. Kim Jong-un has never been to Beijing in his leadership. The Chinese press are saying some amazingly negative things about the north, and about Kim Jong-un. So - so they are weighing in, and they are bringing greater pressure. Whether it will be enough I think remains to be seen.

I think it's kind of a stretch. You know, it's one thing if somebody working for the U.S. government has sold secrets to the other side, it's another if they have something in their personal life that they're hiding for which they could be blackmailed. Having evidence that they didn't tell the truth to somebody in the same building where they work, maybe it's just the old intel guy, is - it's a problem.

I think, on the foreign policy side, that there is a need for disruption. We've had three administrations follow a pretty consistent policy toward North Korea, and it really hasn't gotten us anywhere.