Why do countries desire nationalism?

Because they believe in the superiority of their shared attribute, nationalists often stereotype different ethnic, religious, or cultural groups. The resultant prejudice keeps their nation unified. Intolerance can lead to a desire to rid the country of those deemed as "different." In an extreme form, it can lead to ethnic cleansing and genocide.

Explanation:

early settlements on the subcontinent. both the indus and the ganges rivers carried rich silt from the mountains to the plains. when the rivers flooded, the silt spread over the plains and made the soil in the river valleys fertile for farming.

the language of nature was a manifestation from god as he said "let there be light" and there was light the world began to assume visible, comprehensible form.

what ever we know now think of the old vision of creation we can be sure that with out the speaking of word -without language- we would have no science today with its striking power to illuminate the world.