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.

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.

In this age, I don't care how tactically or operationally brilliant you are, if you cannot create harmony - even vicious harmony - on the battlefield based on trust across service lines, across coalition and national lines, and across civilian/military lines, you need to go home, because your leadership is obsolete. We have got to have officers who can create harmony across all those lines.

Our world is becoming darker. The dangers are increasing from North Korea, whose recent provocation underscored the need to impose a higher price on this rogue regime, a problem that is not just the United States alone, but a problem for us all.

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.

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