It is axiomatic that we differ on opinions, values, and weltanschauung. If we assume that nationalities or peoples have shared heritages and a semi-common culture, then when our course is run as a nation-state, and historians write about us in the near or distant future, what will they tsk-tsk about, and pronounce as our failings as a people? That is, if there is a God, what sins are we most likely to be on the carpet for commiting?
Or, to put it bluntly, just how did we screw it up most?