Those attempting to understand what is coming out of Iran today need to appreciate the extent of which the region of Persia has served to foster militaristic messianic movements. It is actually not just Islamic movements. In terms of Jewish history, this region gave us Abu Isa in the eighth century and David Alroy in the twelfth century. In many respects Persia can be seen as the Islamic world's equivalent of medieval Provence and Italy, regions beloved by modern medievalists for their tendency to do fun things like produce heretical movements and popular revolts. In trying to wrap my head around Persian history (both in terms of my modern interests and in trying to understand the context for the Jewish messianic movements in this region) there seems to be a number of factors that parallel the Southern European situation and have helped contribute to this state of affairs. I am mainly interested in medieval Persia, but these things seem to continue to be relevant to modern Iran.
The ghost of an ancient advanced culture.Italy and Provence were the parts of Western Europe in which the Roman Empire exercised the strongest influence. In many respects, even after the collapse of the Western Roman Empire, the symbols of the Roman Empire did not go away, particularly in terms of physical monuments. Besides for centralized government bureaucracy, the other thing that the Romans did better than anyone else in pre-modern history was to build. One of the things that have struck me about Ahmadinejad of Iran is the close personal connection he feels to ancient Persia. This is perfectly understandable. The papacy still claims the title of Pontifex Maximus, high priest of the ancient Roman pagan religion. Persia was certainly a culture equal to Rome. The Parthian Empire was, for the most part, more than a match for Rome militarily. Do not underestimate our Iranians; they are a very sophisticated people, just the right amount to be both intellectually and militarily dangerous.
The absence of a strong government.Medieval Italy was a collection of city-states. There was no unified Italy until the nineteenth century, a galling reality for classical republicans like Machiavelli, with dreams of reconstituting the Roman republic. Provence was outside the authority of the French monarchy until the thirteenth century. Not unsurprisingly, Provence was brought into the orbit of the French monarchy due to the Albigensian Crusade, when French forces came south to eliminate members of the Gnostic Albigensian sect, branded heretics by the Church and the original targets of the Inquisition.
Since the downfall of the Sassanids up until modern times, Iran has had periods of strong centralized rule, for example the Safavids in the sixteenth and seventeenth centuries. That being said, the dominant narrative is one of a region outside of the major centers of power. While Iran converted to Islam, it successfully resisted Arabization, maintaining a Persian culture. (The number one thing I repeat over and over again to my students is that Iranians are not Arabs. They do not speak Arabic, they speak Farsi.) Furthermore Persia managed, in the long run, to resist Arab military control. The Umayyads and later the Abbasids were never able to establish a firm control over the region. Unlike almost the entire Arab world, Persia managed to resist Ottoman control. This left Persia as a haven not just for Twelver Shiism which eventually became the dominant mode of Islam, but also numerous other brands of Shiism for Zoroastrianism, which survived the Islamic conquest. In terms of Jewish history, Persia was a major center of Karaism.