I am a great admirer of Dr Lipstadt and she has done a lot of fine work, but she falls into the same trap that many "experts" on the Holocaust fall into...the Holocaust becomes their personal property and no one is allowed to use it without their permission and official commentary. The Holocaust affected a LOT of Jews, particularly in Israel...its memory is burned into them and this has been handed down to later generations, more than it has in the US where Jewish family connections are much weaker. Thus, if an Israeli sees what Ahmedinejad is saying and sees mobs in Iran screaming "Death To Israel!" it is not farfetched to compare them to Nazi Germany, even if the comparison is not a good one. If the Iranians don't want Jews to think they are Nazis it is up to THEM to prove their peaceful intentions...something they refuse to do.
Rohani: Nuclear deal achieves Iran's goals (AP)
from the article: Full Interview with Holocaust historian Deborah Lipstadt