Why does man make countries? What is patriotism?

The following is an excerpt from a samvaad (dialogue) session with Acharya Prashant.

Question: Sir, can you give your views on nationalism and patriotism?

Acharya Prashant (AP): See, man always requires something to separate him from others. In this separation is the protection of his ego. If I were just the same as you, how will you say that I am ‘I’ and…