Hinduism IS the only oldest organised religion still practiced on earth. Unlike other religions, it is not only a set of written dogmatic beliefs but a way of life for its followers, the Hindus.
This 'way of life' a.k.a Hinduism was widespread, it not only included modern day Pakistan but Afghanistan as well.
Hundreds of years before the Muslims invaded India, Buddhism was formed out of Hinduism(Lord Buddha was the son of a Hindu king-Suddhodana) and if Hindus persecuted Buddhists then it could not have spread so far and wide throughout India where Hinduism already prevailed.....from Buddha's birth place Lumbini(modern day Nepal) to Afghanistan(the presence of Buddha statues-destroyed by Talibans in Bamiyan-Afghanistan is the proof).
It is the Muslims who persecuted thousands of Hindus and Buddhists when they first invaded India from the north-east.
They totally wiped out the Hindus and Buddhists in those areas (there is a mountain named HINDU KUSH in Afganistan- - - -acc. to Persian-English dictionary, A Practical Dictionary of the Persian Language, by J.A.Boyle, Luzac & Co., p.129, 1949) indicates that the word 'Kush' is derived from the verb Kushtar - to slaughter or carnage. Kush related to the verb Koshtan meaning to kill. In Urdu, the word Khud-kushi means act of killing oneself (khud - self, Kushi- act of killing). Hindu Kush means "slaughter of Hindus", referring to the genocide committed by Islamic invaders.)They continued their invasion towards central India and in the process killings thousands of Buddhists and Hindus. The Buddhists, being non-violent were completely wiped out from these areas, the Hindu kings proved somewhat more resistant in eastern and southern India and they survived the Muslim onslaught, thus helping Buddhism from total extinction in eastern and southern regions of India, consequently from the eastern region, Buddhism spread to countries like china, japan etc and from southern India it spread to countries like Sri-lanka etc.
So you see, who were the actual killers!!!!!!
Most historians and scholars agree to the fact that Buddhism was already on the verge of extinction when the Islamic invasions took place and these invasions did no good to this religion. Islam was a late entrant into India, and Buddhism was showing unmistakable signs of its decline long before Islam became established in the Gangetic plains, central India, and the northern end of present-day Andhra and Karnataka.During the Muslim Invasion, Bengal and Sind were ruled by Brahminical dynasties but had Buddhist majorities. Buddhism was in a state of decline by that time.The lower caste and outcaste Hindus, who had recently taken refuge in Buddhism, were again subjected to discrimination by the upper caste Hindus.
