I know about the Safavids, you're right and I am not disputing that. I was specifically talking about the Hashashins only, i.e. they weren't an outside force. Hashashins existed in Alamut since 1080's whilst Safavids came in 1500's.
While Safavids were aiding Mongols....Hashashins were fighting them and in the process they got wiped out.
Savafids were the main beneficiary of Mongol invasion. Savafids attacked the Ottomans when the Ghazis were in the suburbs of Vienna well. On the record, Henry said "If it was not the Savafids attacking the Ottomans from the east, we would be reading Quran today". 300 years ago Iran was a majority sunni country, After Savafids took over Iran. They force majority to convert to Shiaism.
Nowhere in the Muslim World any country has declared "Sunni" as a state religion, but Iran has declared Shiaism as State religion.
Sunnis are not even allowed to built a Masjid in Terhan.