Wu [a guy who was starting a rebellion against the Qing] offered Emperor Kangxi an amnesty if he would only leave Chinese soil altogether and found a new kingdom in Manchuria and Korea. Predictably, Kangxi refused, and to underscore his anger he executed Wu’s son, who was being held hostage in Peking.

I have a take, which is that if you’re going to take someone’s kid as a political hostage, you should send them back home for about three weeks a year so that the family can become emotionally re-attached to the kid. This has the ~upside that if they refuse to send the kid back, it’s a pretty good indicator that trouble is brewing.