I didn't know that India is a "small nation in SE Asia"!
Anyway, the best way to treat India is to ignore it. If you try to be nice to it, it will want to believe that you are trying to suck up to it, and play hard to get. If you try to be tough to it, it will give it a sense of self-importance beyond its real worth.
So, just ignore it! That will make it feel most insulted.