Just the existence of mass movements like the above(which is not isolated) refutes the Buddhism -> karma -> fatalistic acceptance that was postulated in the first comment try to establish a link with tyrannical governments.
Just living in any of these countries, one will see the constant effort of people, even hustling, to get ahead in life, far from any fatalistic conceptions one might have about their life.
I can, in fact, think of other examples of worse brutality, even in the last few centuries, for instance the American slave system and treatment of labourers in Congo. Not quite the same extent, but still terrible, the British had an indentured labour system transporting Indians whose local lands were devastated by colonial rule. I wouldnt casually attribute these to religion of the westerners.
This kind of violence hasn’t been common in other parts of the world for centuries. It’s also a phenomenon that is distinct to states in South East Asia - and, in fact, to the Buddhist states in South East Asia ( it was not practiced in what is now Malaysia in Indonesia - which are now Muslim and before that practiced a religion that mostly resembles Hinduism).