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.

2017 is going to be another tough year for the valiant Afghan Security Forces and the international troops who have stood and will continue to stand shoulder to shoulder with Afghanistan against terrorism.

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.

You've been told that you're broken. That you're damaged goods ... there is also Post-Traumatic Growth. You come back from war stronger and more sure of who you are.

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.

Nothing keeps me awake at night. I keep other people awake at night.