Last time I checked, Rommel was a Field Marshal in the German armed forces, and commanded Afrika Korps
Rommel only decided to assasinate Hitler when it came to the end of the war and the Germans begun losing, many of Hitler's advocates suggested that he accepted defeat and surrended.
Rommel swore his allegiance to the German Empire, (WWI) Weimar Republic (Post WWI govt.) and then Nazi Germany.
"Nazi" is such a harsh word, people assume that they were evil and taking into acount the whole German population was under the Nazi rule, so hypothetically the whole German population is evil. But take the SS for example, normal men... trained to become to elite of the Third Reich ended up becoming murderers from their actions but originally were just normal men.