>> if we think the government of a bigger nation which is responsible only to its own citizens can act to protect everyone's interests.

In the case of India it does. Even though it is changing and they are unfortunately adopting the individualistic philosophy of the west..

When the UNSC was being setup post WW-II, India canvassed against its own candidature for China

After testing its N Bomb, it gave up working on it actively to help build a N free world. Willingly stated a no first use principle.

Released 92000 Pak PoW after the 1971 war for no quid pro quo.

You don't hear these stuff in western media. Hell, we don't hear of regular state and federal elections held in the world biggest democracy.

to get an idea of what I am talking about and how the Indian philosophy is rooted in us all being one. https://www.youtube.com/watch?v=3srSwuG9kVw