As Xi Jinping sat across from Joe Biden in San Francisco on Thursday, as momentous a meeting as it was, he could be forgiven for having more than half an eye a world away, on the political upheaval in Taiwan.

The status of Taiwan is strewn with landmines for any political leader, be they Chinese, American or Australian for that matter, because of the heavy historical baggage the island has been forced to carry for more than a century.