1) It's one thing to say something about a country(France & Prussia), it's another thing to talk about a race(Africans). Take a look at Youtube's attempt at defining hate-speech in their guidelines:
""Hate speech" refers to content that promotes hatred against members of a protected group. For instance, racist or sexist content may be considered hate speech. Sometimes there is a fine line between what is and what is not considered hate speech. For instance, it is generally okay to criticize a nation, but not okay to make insulting generalizations about people of a particular nationality. "
(Note that I think Google should remove the "protected group" part and just say "any group of people")
2) How far down this endless rabbit-hole are we going to go? I can't prove to you the nature of any group of people, anymore than you can prove to me that you're not just another racist/troll that always shows up during conversations about Africa or African-Americans on Google+, on Reddit, on HN or any other site that always ends up derailing the main topic into oblivion.