No president is well-served by groupthink or by everybody singing from the same sheet of music they think he's on.

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.

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

Power... Military success is not sufficient to win: economic development, institution-building and the rule of law, promoting internal reconciliation, good governance, providing basic services to the people, training and equipping indigenous military and police forces, strategic communications, and more of these, along with security, are essential ingredients for long-term success.

When I was the director of Central Intelligence in the early '90s, I tried to get the Air Force to partner with us in building drones. And they didn't want to, because they had no pilots.

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.

One of my favorite little sayings is, 'To avoid criticism, say nothing, do nothing, be nothing.