بسم الله الرحمن الرحيم
The fact that the Arabs have largely turned their backs on Islam was predicted by Allah Most High when He said:
وَإِن تَتَوَلَّوْا يَسْتَبْدِلْ قَوْمًا غَيْرَكُمْ ثُمَّ لَا يَكُونُوا أَمْثَالَكُم۞
And if you turn away He will replace (you with) a people other than you. Then they will not be like you.
The Prophet’s Companions asked him who those people would be that would replace them (the Arabs), to which he responded by patting the shoulder of SalmanRA the Persian, and said:
هَذَا وَقَوْمُهُ هَذَا وَقَوْمُهُ
“This one and his people! This one and his people!” (Jami al-Tirmidhi #3260)
And in the subsequent narration:
هَذَا وَأَصْحَابُهُ وَالَّذِي نَفْسِي بِيَدِهِ لَوْ كَانَ الإِيمَانُ مَنُوطًا بِالثُّرَيَّا لَتَنَاوَلَهُ رِجَالٌ مِنْ فَارِسَ
“This one and his companions. By the One in Whose Hand is my soul, if faith were suspended from the Pleiades, then it would be reached by men of Persia.” (Jami al-Tirmidhi #3261)
Interestingly, the Prophet ﷺ did not merely say that Salman’s people (the Persians) would replace the Arabs in being favored by Allah for their service to His Religion, but that sayyidina SalmanRA himself will also have the honor of being chosen by Allah Most High to be the instrument of His Will in replacement of the Arabs who “turn away”. Historically, the Persians and Iranians rendered great services in the cause of Islam, particularly in the field of academia, and they also produced many men of piety and saintliness. Tragically, most of the Persians were converted to a distorted brand of Islam, i.e., “Twelver Shi’ism” during the reign of the Safavids, but some of the other Iranians, particularly in the northeast, remain steadfast upon the Sunna. The Tajiks and Persians of Afghanistan, and perhaps along with other Iranic groups like the Pashtuns, Baluch and Kurds, constitute those people concerning whom the Prophet ﷺ said that from among them there would be men who reach the heights of the Pleaides in the level of their faith, and Allah knows best.