I would like to add that I'm in full agreement with everything that Professor Maley said. In addition to not being a reliable source of protection and being quite abusive towards Hazaras, Iran....
There is not really any mechanism for Hazaras to gain permanent asylum in Iran, despite the fact that they have the same Shia religion. People, refugees who have been in Iran even for generations, Hazaras who have been born in Iran, often find themselves just depending on the whim of the government. All of a sudden they are in the same situation where they might be facing deportation or might be facing something else. You find that not only are Hazara refugees fleeing Afghanistan but also there are a number of Hazara refugees who are fleeing the situation in Iran, which they may have actually been born into, so Iran definitely can't be counted on.