Im really not sure how effective it is. Im sure it helps smooth over small things but I doubt anything truly serious would ve fixed by China dangling the pandas over western countries. Though a zoo that has a panda is increasingly rare which in turn would be a tourism draw so I doubt any state/country that has one would want to loose it. Im often extremely surprised at how many politicians etc that are willing to roll over and do China's bidding.

All Pandas are more or less "owned" by China. They "rent" them out (for the entire lives) to other countries. Im not positive but I think they also send people out to both check up on the pandas and take them back if that country has displeased the CCP. They basically use them as political bargaining chips from what i can remember.

I remember when i was younger getting weed was wayyy easier then getting booze. It was probably cheaper too in the long run.