Afghanistan before Islam was the site of ancient and magnificent civilizations, of which the famous Bamian Buddhas (destroyed by Taliban tank fire) are but a remmnant. Winston Churchill, campaigning through the Swat valley in 1897, wrote:
"In ancient times this region was the seat of a Buddhistic kingdom, and was known as Woo-Chang or 'Udayana', which means 'the Park' and proclaims the appreciation, which its former possessors had of their pleasant valley. 'The Park', which includes all the country on both banks of the Swat River, was famous for its forests, flowers and fruit. But though the valley retains much of its beauty, its forests have been destroyed by the improvidence, and its flowers and fruit have declined through the ignorance, of the fierce conquerors into whose hands it fell."
Perhaps archaeologists of the far future will find, to their surprise, that the Hagia Sophia mosque was formerly a Byzantine Cathedral and that the ruins of a great city lies under the dusty goat tracks of Man El-Hattan.
There are many "Persians" now resident in the United States. I have met some who have told me they feel the same way about their homeland, Iran and its culture. That is, the flower of their once high civilization was crushed by Islam.