Most the threads I've seen here make the assumption that if the CSA had won the war, it would have lost the peace. The reasoning is very sound, the south lagged behind in terms of industry, couldn't coordinate the federal government very well, and would have massive internal racial and class problems.
It seems to me that the assumption is that the CSA couldn't survive because it couldn't achieve parity with the US. What if it didn't have to? I remember reading that the CSA was, in terms of industry, on a par with the Austro-Hungarian Empire. It didn't have the same level of internal division, and it's in a much more secure position geographically if relations normalise with the US.
Could a neutral CSA that focuses mainly on internal affairs and maintaining security on its southern border survive the 20th century without revolution, collapse, or vassalship to the USA?