We have no reference for what happened in those countries back then. For most people they are just words that relate to a vague series of events. Try to imagine the deaths of tens of millions of people in all manner of ways; some of them truly fiendish. Those who have looked deeper into the historical record know what I am talking about. You can't imagine it. The imagination doesn't have the facility to wrap around something like that in the consciousness of most people. Most people wouldn't give it a second thought anyway. If it's not happening to them, it might as well not be happening at all.