Can anyone come up with a short description of what Nationalist China would look like decade by decade after a victory in the Civil War with the Communists totally defeated or at least reduced to a guerrilla movement?
There was an attempt to examine what such a China might be like in What If?, ed. Robert Cowley. It was written by Arthur Waldron (who seems to be somewhat biased), and seems interesting, I don't know if that would be useful for you.
I haven't read it for a while, but I will come back with a more detailed summary when I do. He provides two possible PODs (as we would call them: either Chiang, in 1946, does not pause outside Harbin, thus not giving the Communists time to regroup; or, he chooses not to invade Manchuria in the first place, leaving it for the Communists to have. Waldron seems a little unclear on why Chiang might have done the latter, but in any case he reckons the result would have been much like the East/West Germany situation: a capitalist Republic of China, and a Communist 'Chinese Democratic Republic' based in Manchuria.
Waldron reckons that Manchuria would initially have done well by itself - it had plenty of industrial resources, as well as industry itself, and good farmland. But Nationalist China would have industrialised, then caught up with and overtaken its neighbour, gradually democratising along the way, much as South Korea did. He cites various examples,such as the way China's economy boomed in OTL once "the worst of Communist policy" was abandoned in the 1980s, and also reckons that the port cities being open to foreign trade in the 1950s would have been a further impetus to growth.
He thinks that, in such a situation, Nat. China/CDR would have been a generally stable Cold War battlefront in the same way the FRG/GDR front was. And that it may in fact have helped end the Cold War quicker, since as the CDR's economy began to atrophy along with the rest of the Warsaw Pact, the USSRwould have had to try to prop it up.
I don't know - does all this seem plausible?
I would have to say there are few scenarios which would not result in some kind of strong Communist underground, at least initially. This likely would be Nationalist China's most prominent domestic concern for many years.