We have the most skillful, firecest, and certainly the most ethical ground forces in the world... I'm not saying we have to commit right now, but certainly don't pull it off the table.

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.

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

You cannot allow any of your people to avoid the brutal facts. If they start living in a dream world, it's going to be bad.

Anyone who kills women and children is not devout. ISIS cannot dress themselves up in false religious garb and say that somehow this message has dignity. We're going to strip them of any kind of legitimacy.

The United States has been essentially engaged in an ongoing war that most people date from 2001. That war has taken us to Afghanistan, to Iraq, in a lesser way to other countries - Libya, Somalia, Yemen.

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.