My great grandfather was in the ww2 he was a soldier on the Italian army , was he a nazi if he was on the Italian army ?

by acmlko
BruceWareAllen

Highly unlikely, unless by a very uncommon personal preference. (Indeed, he would not necessarily have been a nazi even if he had been in the German army.)

By the way, if you're interested, the classic novel of the Italian army during the second war is Eugenio Corti's The Red Horse, based on the author's experiences fighting the Russians.