As you acknowledge, the advance of colonialism caused a gigantic reduction in state and private violence: See for example Abdullah Munshi’s vigorous condemnation of the pre colonial era that he personally experienced.

As you neglect to acknowledge, the retreat of colonialism caused a gigantic increase in violence, as has the democratic era generally, with murder rates rising substantially since universal sufferage began, and massive increases in crime and imprisonment.

See my post: http://blog.jim.com/culture/pinker-on-violence.html