The chinese probably waited until Arizona was declared formally for Biden. Since Trump has not formally conceded anything they had to account for the possibility that Trump might be able to overturn Pennsylvania. If Arizona has gone Biden its getting increasingly unlikely Trump might be able to do anything. Countries like China and Russia are ultimately ruled by individuals who need to account for the possibility of war with the US. Congratulating Biden when it still seems theoretically possible for Trump to win would be dangerous. Now if Trump wanted to overturn the election results he'd have to use the Army in order to enforce it which means civil war. It was still possible in theory to do that without the Army as long as Pennsylvania still seemed in play but with Arizona going Biden its clear that if Trump wanted to overturn the results its impossible without massive bloodshed at this point. The chinese aren't stupid they were cautious.From an other angle we could wonder what it took so long for Xi the Pooh to congratulate Biden compared to Macron who acted more quickly?![]()