But Arnold Kling, as usual, says it best. I like all of Arnold's points, especially this one:
I believe that civilization is a fragile thing. It is easy to imagine a more peaceful world. It is easy to imagine a less nationalistic world. But I find it even easier to imagine a world that is worse along both dimensions. My guess is that if the United States becomes less nationalistic and less assertive, then the world as a whole will take a turn for the worse rather than for the better.