> the "One China" policy ensures neither the Republic (in Taiwan) nor the PRC will allow the other to be a UN member at the same time as them.
Actually, 90+% of the population of the ROC, including their leaders, would be ecstatically happy to be an UN member separately from the PRC. The only reason they officially have a "One China policy" is that the PRC has made it clear that while they can tolerate the status quo of a rival government with zero prospects of actually challenging them controlling a small piece of their territory, they will very much not tolerate that piece of territory to become officially independant and provide an example for at least half a dozen others.
Actually, 90+% of the population of the ROC, including their leaders, would be ecstatically happy to be an UN member separately from the PRC. The only reason they officially have a "One China policy" is that the PRC has made it clear that while they can tolerate the status quo of a rival government with zero prospects of actually challenging them controlling a small piece of their territory, they will very much not tolerate that piece of territory to become officially independant and provide an example for at least half a dozen others.