I'd also add that another way of reading the importance of Taiwan towards the PRC would be in light of other ideas that didn't matter to the CCP in the 1940s but became important to the CCP as leaders tried to figure out what the party's relationship with Chinese national identity would be. Take characters -- Mao was all for getting rid of them in the 40s and 50s and replacing them with a romanized alphabet that would make it easier to increase literacy since that was a pretty rational position, but then the Cultural Revolution made it an idea-non-grata and the idea of replacing characters with a romanized alphabet became anathema to the CCP's sense of identity. I recognize that there is far from a perfect one-to-one correspondence between the CCP relationship with hanzi and the CCP relationship with Taiwan, I just think it is interesting to think about the Taiwan question in light of a bunch of other areas in which the CCP changed its mind, because what's important to any nation state's sense of identity is as much a matter of myth and expediency for powers that be as it is a matter of saying "it's always been important to us because how could it not be important to us!" And yes that puts all of these thing's into Hayton's light of anti-CCP historical nihilism.