That's no accident though. Divide and Conquer was a core conquest and governance strategy for the British Empire, one that has left scars across the world that are still causing conflict today.
Because some of us can still see the Northern/Republic of Ireland divide and realize that wasn’t an existing divide, but created entirely by the British? Then there’s how they handled Israel, but that’s too much of a can of worms to open here.
Don't stop with the British, European colonialism is responsible for the majority of issues we have in the Middle East today. Even African is still recovering after the mess left there.
India has always had conflicts between communities with 100s of individual kingdoms and warlords - some were vassals to bigger kingdoms. The modern day revisionist history tries to paint India as some sort of a united, utopia before the coming of the colonial powers but there is no evidence whatsoever to support that claim while there is plenty of evidence to counter it.
I don't think you are saying that India was never a united entity in it's history. It has been united multiple times throughout. In fact that's how it got the name "Bharat" after one if the kings.