Bah!ASB. China, one or the other but only one, has a UN Security Council veto. By the time Taiwan becomes a democracy in which seperatists can come to power, its the PRC that has the veto and will block any attempt to split the country.
Not to mention that even if China somehow lost its security counsl seat, its hard to imagine the UN refusing to back down in the face of a joint statement on the oneness of China from both governments.
Bah!
All that needs to happen is that Nixon recognizes both Communist China as China - and Taiwan as Taiwan (and an American ally). That's only recognizing reality. Yes, both Chinas would be truly annoyed, so what?
Then Nixon completely wastes an opportunity to give the Soviets a prominent middle finger through a rapprochement with Beijing, pisses off both Chinas rather than just one and throws away any potential Chinese cooperation in ending the Vietnam War. If Kissinger doesn't shoot him first.
And Nixon is not the UN, so what does this have to do with it?
Because the US veto is what kept the seat from changing.