1. In Germany at the time the predominant attitude seems to have been that most people didn't want to know: 'hear no evil, see no evil' seems to have been a very widespread attitude among many of those who were not involved. 2. In Britain and the U.S. news of the Holocaust was at first met with skepticism, but then became widely known. However, it wasn't emphasized but at the time (or in the aftermath of World War 2); it was regarded as one of the most serious crimes committed by the Nazis - roughly on a par with launching a war of aggression.