I think, broadly speaking, the US military's role - US military activism in various parts of the Islamic world over the past several decades has been counterproductive.

Actually, it's a lot of fun to fight. You know, it's a hell of a hoot.

Since 9/11 we've been engaged in wars around the world, and General [James] Mattis has been a leading battlefield commander in many of those theaters, including in the April 2004 siege of Fallujah, where the US Marines killed so many people that the municipal soccer stadium in the city had to be turned into a graveyard for the dead.

We can kill lots of people. We do kill lots of people. We can destroy virtually anything we choose to destroy.

No war is over until the enemy says it's over. We may think it over, we may declare it over, but in fact, the enemy gets a vote.

With respect to the outlines of what's in the Army Field Manual, there's no doubt in my mind about the limitations it places not only on the DOD, but on the Central Intelligence Agency. And I'll always comply with the law.

We face now an era where we're going to be fighting the terrorist threat. I mean, that's simply a reality we are going to have to address that one.