Here's something which is probably obvious but which also struck me with new force as I stepped, completely naked, out of the shower this evening:
Disagreement over ideology is displaced tribalism. The self-image of "civilized" parts of the world has evolved to the point where it is unacceptable to seek conflict with other cultures based solely on naked difference. As a result, we, s0me of us, seek to identify profound moral flaws in the political systems of other cultures in order to justify our desire to attack/fear them.
In a weird way, I can see how this makes me a believer in realpolitik.