Before you read that wall of text: Countries in Hetalia are representing stereotypes, and as far as I know, a typical German is not a Hitler adoring Nazi.
In Hetalia, countries do what their bosses order them to do. America told the world that the UFO, which was found, was only a weather ballon (Assault☆The neighbor’s Roswell Incident), because his boss told him to do so.
So, you could say, Germany is not a nazi, because he just did in WWII what his boss (you know which one we're talking bout) ordered him. But of course, you can't kill people and hate them with passion, and 50 years later, you are an entirely different person. But you have to keep in mind: Germany is not a single person. He was a soldier on the battlefield, he was a lonely widow in some village, he was a person, who hated Hitler and the Nazism, and he was a person who admired Hitler and loved the Nazism. But he didn't was a country consisting of 74 millions Nazis. What matters is, out what kind of people Germany exists today. And that's, like with every other country out, difficult to say.
Sorry for my English ;3;