As a longtime career guy, I like quiet diplomacy behind closed doors. This is not what we're getting with Donald Trump. At the end of the day, it's what America does, how people perceive us, in the long run, our reliability and such, and, thirdly, the personal relationships presidents have with their counterparts. The tweeting and some of the explosive conversations can hurt the third and can have an impact on the second, but, in the end, what we really should focus on is the policies. Some of them have been bad, the rollout of the immigration ban. Others, we have to wait and see.

There are real issues that the president Donald Trump and particularly Steve Bannon, his political adviser, are pushing. It's a vision, a rather dark vision, of a 19th century world where great powers do transactional issues.

The NATO alliance is not just a transactional relationship, once again. That alliance serves our interests. That alliance has been critical to keeping security in Europe, so that we do not face another world war.

I'm concerned about Donald Trump's relationship with Russia that ignores Russia's aggressiveness in its near abroad. I'm concerned about the willingness to question alliances and the value of allies, or require them to pay more, or they don't get to play.

I know that presidents often have really bad phone conversations. What they usually don't do is go out and talk about it. That gets to my point about doing some damage on the periphery of our core policies.

At the end of the day, it is what Donald Trump does or doesn't do as crises come up and as he tries to advance his agenda. He can hurt it on the margins by this kind of talk. That's my view. He could help it with a different approach to our allies and friends and our foes.

NATO is in our national security interests. And, yes, we pay a lot for it, but, when we had Afghanistan, NATO troops were by our side from almost all of the NATO members. And they put their life and treasure on the line for us.