Same thought occurred to me as I was searching for counterexamples.
My initial hypothesis is that civil wars fought over economic systems tend to result in reunification afterwards with the more efficient economic system establishing hegemony over the less efficient one, while civil wars fought over culture tend to result in universal ruin. So the U.S. Civil War was ultimately a contest between manufacturing (Union) vs. slave plantations (Confederacy), and the Union won and re-established hegemony because it was better able to mobilize its railroads, arms production, shipbuilding, etc. There are a few other examples that support this, eg. the Russian Revolution pitted the feudal landed aristocracy against the urban industrial working classes, and was won by urban industrial working classes, who subsequently reunified the country (at least until Communism fell apart in 1991).
That hypothesis can't explain why the Reds defeated the Whites in the ensuing Russian Civil War, though - the White coalition included large numbers of the liberal urban bourgeoise. It also can't explain why the Communists defeated the Nationalists in China, yet subsequently adopted an economic system much more like Taiwan. And it doesn't explain why the English Civil War (which was Catholic vs. Protestant, like the 30 Years War) was comparatively bloodless and resulted in greater unity rather than disintegration.
I wonder if it may have something to do with the organizational abilities of the leaders (the Union, Bolsheviks, and forces of William of Orange were all quite well-organized compared to their adversaries), or of the relative power balances between them. Both of these are still fairly unsatisfying as answers though.
My initial hypothesis is that civil wars fought over economic systems tend to result in reunification afterwards with the more efficient economic system establishing hegemony over the less efficient one, while civil wars fought over culture tend to result in universal ruin. So the U.S. Civil War was ultimately a contest between manufacturing (Union) vs. slave plantations (Confederacy), and the Union won and re-established hegemony because it was better able to mobilize its railroads, arms production, shipbuilding, etc. There are a few other examples that support this, eg. the Russian Revolution pitted the feudal landed aristocracy against the urban industrial working classes, and was won by urban industrial working classes, who subsequently reunified the country (at least until Communism fell apart in 1991).
That hypothesis can't explain why the Reds defeated the Whites in the ensuing Russian Civil War, though - the White coalition included large numbers of the liberal urban bourgeoise. It also can't explain why the Communists defeated the Nationalists in China, yet subsequently adopted an economic system much more like Taiwan. And it doesn't explain why the English Civil War (which was Catholic vs. Protestant, like the 30 Years War) was comparatively bloodless and resulted in greater unity rather than disintegration.
I wonder if it may have something to do with the organizational abilities of the leaders (the Union, Bolsheviks, and forces of William of Orange were all quite well-organized compared to their adversaries), or of the relative power balances between them. Both of these are still fairly unsatisfying as answers though.