so from 1948 till 1979, supposed Iranian Nazism was dormant, but suddenly popped back into the air immediately after the revolution?
uh huh. forgive me if I an unconvinced.
Ahmedinajad may be a bigot and a Holocaust denier, but Iran is not a nation of Nazis and Nazi emulators.
It all relates to just
what aspects of Naziism were the ones that appealed to those Iranians that embraced it. Even Naziism is a complex enough ideology (in terms of structure, not depth of philosophy) that it's not an everything-or-nothing proposition.
Reza Shah was sympathetic to Hitler, because Hitler's views on "Aryan supremacy" matched very well with Reza Shah's own views. However, while this sympathy allowed Nazi Germany to make inroads into Iran, the non-supremacist aspects of the ideology did not gain nearly as much traction, simply because that's not what the Iranians really
cared about.
That's why, from 1948 to 1979, the anti-Semitic aspects of Naziism did not remain prevalent in Iranian social and governmental policy, because the Iranians cared more about the "Aryan ethnosupremacism" aspects. And in Iran, that meant focusing on all the non-Persian minorities, of which Iranian Jews were just one among many. The Shah didn't single out the Jews, because they weren't worth singling out - Iranian racist ideology was simply not built around the framework of anti-Semitism the way Hitler's racist ideology was. And so, without the strong, active, propaganda influence of a strong, active Nazi regime, Nazi-esque anti-Semitic policies didn't exist in Iran because they didn't matter to Iran and its own particular idea of what "Aryan supremacism" meant (which, despite similarities, was not really what Hitler meant by the term).
That's also why, in the post-1979 era, when anti-Semitism showed up again, it expressed itself as neo-Nazi sympathies. The anti-Semitism of the Islamic Republic wasn't the anti-Semitism of Hitler, but the anti-Semitism of a Muslim state that was simply one among a number of other Muslim states, locked into a cycle of conflict with the Jewish state of Israel. But Iran had that long history of Aryan supremacism that the Arab Muslims states did
not have, so when the now-strongly-anti-Semitic Aryan-supremacist state of Iran went looking for people who shared its views to ally with, they
found strongly-anti-Semitic Aryan-supremacist groups already there, waiting for them: neo-Nazis.
EDIT: They don't share the same type of "Aryan supremacism", nor the same type of anti-Semitism. But they're congruous enough in both aspects to make it a lot more understandable as to why they're allying in this fashion.
In short, Iran didn't simply hide and incubate Naziism during the 1948-1979 years, until it burst forth in a brand-new infection during the modern Islamic Republic era. It's that the particular form of autocthonian "Aryan" ethnocentrism of Iran makes the Aryan-supremacist ideologies of Naziism more palatable in that country than it would be in other countries that don't have a history derived from the same 19th-century crackpot racist and ethnic Aryan-origin theories that also gave rise to Naziism.
Throw in some virulent anti-Semitism (and a reason for it to be so widespread, such as linking it to a sense of anti-Westernism and pro-Islam identity among the populace, with the state of Israel as a focus for those sentiments), and the Iranian government's tacitly endorsing neo-Nazi websites and groups starts to sound even
less surprising.
