That's not what the study says. It's more: short-term pain and maybe (hopefully) less pain in the long-term. Besides, I'm not sure how applicable the examples

That's not what the study says. It's more: short-term pain and maybe (hopefully) less pain in the long-term. Besides, I'm not sure how applicable the examples given in the study are to a modern nation state. (You can't run a nation like a military, and religion and nationalism are on the decline, so those are probably not sources of future social cohesion either.)