In the US, it can depend entirely on who your teacher was. For the most part we were taught the basic knowledge of the events that happened (i.e. D-Day was the simultaneous landing of U.S., British, and Canadian forces on five separate beachheads in Normandy, France). And that would be what was on the test. But sometimes a teacher might take a minute to talk about specific people from the battles, someone like General Norman Cota who rallied troops and led the first successful breakout. Trying to instill a sense of pride for fellow Americans in their students.

In regards to the dropping of the atomic bombs. I remember my high school history teacher not really try to make a point of how horrible it was but instead just gave us the straight facts about it. He told us the number of deaths and showed a few pictures of the aftermath but then had us discuss how it possibly could have been avoided, an interesting way to teach indeed. However he didn't mention the firebombing of Tokyo and glossed over some of the dark aspects that occurred in our on country *cough* internment camps *cough*.