These are all excellent questions! 

Although Pearl Harbour isn’t covered, there is documentation of the nations getting scars from wars and political repression. 

As for natural disasters? While they haven’t been shown to get scars from them, the nations’ personalities are sometimes based on their climate and geography. Iceland is a good example of that. He has a “hot side” of his personality to account for volcanic eruptions/hot springs.

Guide coming up tonight!