It has been a year since President Xi and President Biden last met, and it's hard to overstate just what a rollercoaster US-China relations have been on since then. The fact this meeting is happening at all is the result of months of delicate planning. But for all the "tough-line", "hard-man" images that both men try to broadcast domestically, there is a mutual recognition of one key fact: it would cost more, both politically and economically, to allow relations to spiral. Why now? It was just nine months ago that US-China relations hit what felt like rock bottom as the...