So, back in the 80s, the Prime Minister of the UK, Margaret Thatcher, negotiated the "one country, two systems" agreement with the PRC regarding the return on Hong Kong to Chinese rule, as the treaty that allowed the UK to rule Hong Kong was expiring within a couple of decades.
However, the PRC was not the only legitimate successor government to the court of Imperial China, with whom the original agreement was made - there was also Taiwan, whose government was the successors of one of the losing sides of the Chinese civil war, who survived by fleeing to Taiwan from the Chinese mainland. Additionally, the Taiwanese government was much more democratic than the PRC has ever been, and who are strongly allied to the United States, who are in turn strong allies of the UK.
So, why did Thatcher decide to give Hong Kong back to the PRC, rather than giving it back to Taiwan, thereby removing the need to make a "one country, two systems" agreement in the first place? Surely this would have resulted in a better outcome for the people of Hong Kong, without compromising the democratic and capitalist ideals of the United Kingdom (and Margaret Thatcher's right-wing political party).