If you read carefully then by the time british came to india muslim power was almost finished. Marathas, Jats, Sikhs, rajputs, dogras and hindu kings in assam had already established themselves in power after replacing muslims. Together they controlled 90% of India. Only in avadh, mysore, andhra and bengal were muslim rulers were in power. Rulers of Mysore, bengal and avadh were more of secular nature. So non-muslims were facing persecution by muslims in andhra (or Hyderabad). The british did nothing to stop the persecution here and non-muslims were persecuted even after independence.
Now with regard to unifying India-- India had more princly states when british left than when they came to India.
It was Sardar Patel who is responsible for unifying India. As regards to your notion of natural construct (or natural country) India is a natural construct. a. In terms of geography: India has natural boundries. Himalayas in north, desert in west, dense forests and hills in east, an ocean in south. These natural barriers have guarded India's frontiers. A large number of invasions (including that of "Mohhomad bin qasim" and "Changez khan" were not as successful as they were elsewhere). b. Religiously: Islam is a recent development. All through centuries Indians shared a common bond of religion. Earlier there was hinduism. When Jainism and budhism became strong, hinduism accepted the core values of these to an extent that budhism and jainism became identical to hinduism. Sages like Gautam and Mahavir Jain were revered by hindus also. In hinduism although there were divisions (like shavites and vashnavites) yet the puranas show that the people following shiv and vishnu were related--(Shiv puran: Shiv says - "I shall not be pleased by those who worship me and not vishnu" and Vishnu puran and Bhagvat Puran: Vishnu says - "I shall not be pleased by those who worship me but not Shiva) c.Philosophicaly: All Indians have the tendency to accept what is best practice irrespective of where it is comming from. This is the root cause that Indian civilisation has survived since time eternal. We are not rigid people and our strength is our flexibility. It is most certain that we would have most certainly accepted machines and industrial revolution even without british). d. Genetically: Aryans had originated from Dravidians and were not a separate race that had come from outside and this has been proved by the mitochondrial DNA studies (Published some time back on rediff). The Aryan invasion theory is crap. All people in Indian subcontinent have same gene pool and have originated from dravidians (I know this might prove a bashing point for some).
Of course we have internal conflicts, but then which country in world does not have internal conflicts. Even brothers have conflicts and that is what we are. Tamilians, Jats, Marathas, Muslims, Sikhs, Christians, and all the rest -- we are brothers in one nation.
The concept of purity or uniformity of race as being central to a country is absurd. Pakistan is still trying to achieve purity. It is a mirage. People in a nation shall not be uniform in beliefs, actions and behaviours. Otherwise they might well be robots.
Indian concept of nationhood was "unity in diversity", and a unifying relationship based on justice and fairness, "a duty for the mother land" and not to a race religion of caste.
I hope I have made things very clear. Let me say once again: India was, is and shall remain a nation eventhough thousand civilisations like british shall come and go away.
