Nevertheless, Sir Thomas Arnold does acknowledge that the persecution of Zoroastrians did take place later on. Stepaniants states that many persecutions took place during the reign of the Abbasids, and around that time was when the Parsi exodus took place. But regardless, both Arnold and Stepaniants say that the Islam is not to blamed entirely for the decline of Zoroastrianism.
The original statement notes that Sir Thomas Arnold recognizes persecution of Zoroastrians occurred later on, whereas Stepaniants suggests many persecutions happened during the Abbasid reign, around the time of the Parsi exodus. However, both authors agree Islam is not entirely to blame for the decline of Zoroastrianism.