What concerned me was that [James Mattis] played not only a critical role as a battlefield commander in Fallujah, but also, afterwards, when he was promoted to various other higher-ranking positions, he served as a convening authority in court-martial proceedings against various marines who had been accused of atrocities - for example, in the Haditha massacre, where a group of marines went on a killing spree after one in their unit was killed.

It's quite fun to fight them, you know. It's a hell of a hoot. It's fun to shoot some people. I'll be right up front with you, I like brawling.

I find it disturbing that no member of the Senate Armed Services Committee is willing to acknowledge that record of failure and to ask our next secretary of defense what he proposes to do to amend that sorry record.

Treachery has existed as long as there's been warfare, and there's always been a few people that you couldn't trust.

It is mostly a matter of wills. Whose will is going to break first? Ours or the enemy's?

The destruction that we have wreaked in the various theaters in which we've been engaged is really quite astonishing. But again, lethality, destruction, killing doesn't seem to achieve our objectives. So, my own sense is that a lack of lethality does not define the core problem.

I think as we look at this problem of ISIS, it's more than just an army. It's also a fight about ideas. And we have got to dry up their recruiting. We have got to dry up their fundraising. The way we intend to do it is to humiliate them, to divorce them from any nation giving them protection, and humiliating their message of hatred, of violence. Anyone who kills women and children is not devout. They have - they cannot dress themselves up in false religious garb and say that somehow this message has dignity.