Taboo crisis
Well, we have here in Germany the topic world war 1 and 2 very often as topic in school and it is no shame if somebody mentiones the world wars. Therefore I don't think it's a taboo here in germany. Why does so many non germans think that? I here something like what you said so often ...
I also don't have the feeling Paris attacks are taboo here in France.
Maybe what the article is trying to describe is what are the most traumtic events for each coutry ?