[CMB_polarization]

"In 1962, Davies presented his J-curve theory. He stated that revolutions are most likely to occur when periods of prolonged improvements concerning economic and social development are supplanted by a period of sharp reversal. He used evidence from the Dorr’s rebellion, the Russian revolution, and the Egyptian revolution to support his argument. According to Davies, the sharp reversal of development creates an intolerable gap between what people want and what they get."

http://www.popularsocialscience.com/2013/04/17/james-c-davies-j-curve-theory-of-revolutions/

[CMB_polarization]

For example (from the previous link):

[Maine Mariner]

It is unlikely the Russian Revolution would have occurred if there had not been WWI and the Russo-Japanese Wars.