I don't think the "resource strip-mining" probably wasn't that big a factor.

The big problem was, they used "divide and conquer". The British were masters at it - find a minority in a region, and give them guns and military assistance. The minorities can now be relied on to keep the rest of the population under control, and they can't rebel against the British for fear of a reprisal from the majority.

The problem is, it leaves a real mess when the Brits leave.