hmmm... so you subscribe to the theory of the Aryanic people warring with the local Dravidian/Harappans?
The only way you do not have war is either you perceive the other group as vastly more powerful or if there is someone else around that will pulverize you if you attack them.
By the way looking through my books I found a couple of statues that might have been of great leaders. Or it might have been statues of a not so great leaders.
"Look kids, this is the statue of Og the Stupid who decided to go pet the tiger cubs. Don't be like Og, leave the tiger cubs alone."