I'm not sure how he's supposed to have his finger on the pulse of the national security bureaucracy when he admits that he's a rank amateur.
Categorizing Trump's remarks from the interview as 'maybe we shouldn't defend NATO' is bollocks. The question from the NYT was this: "If Russia came over the border into Estonia or Latvia, Lithuania, places that Americans don’t think about all that often, would you come to their immediate military aid?"
The answer is here: http://www.theatlantic.com/news/archive/2016/07/trump-nato/4...
Underlying this rambling nonsense is the assumption that Russia is some sort of world aggressor.