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.

The importance of strengthening Euro-Atlantic security: the growing dangers pile pressure on our rules-based international system, so we need to do more to strengthen NATO, the bedrock of our defense - not just upping spending, but making the alliance more agile and more capable of tackling dangers from all directions.

I can't imagine that I would be asked that by the president-elect [Donald Trump], or then-president [Barack Obama]. But it's - I'm very clear. I voted for the change that put the Army Field Manual in place as a member of Congress. I understand that law very, very quickly and am also deeply aware that any changes to that will come through Congress and the president.

Ultimately, a real understanding of history means that we face NOTHING new under the sun.

The American people and the American military will never get used to civilian casualties. And we will - we will fight against that every way we can possibly bring our intelligence and our tactics to bear. We're not the perfect guys, but we are the good guys.

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.

When you're in operations, the best thing you can do at the top level is get the strategy right. You have to get the big ideas right, you have to determine what is the policy, what is the level of effort you're willing to commit to it? And then you delegate to those who have to execute that strategy to the appropriate level. What's the appropriate level? It's the level where people are trained and equipped to take decisions so we move swiftly against the enemy.