[TeMPOraL]

IIRC, even they have been forced to increase enforcement of western IP rights over the last decade, because US has been pressuring them to (back before Trump and the whole trade war thing).

This is a generally applicable answer: IP rights hold power worldwide mostly because the no.1 country that wants them has military and economic dominance over most of the planet.

[arp242]

Chinese companies file a huge amount of patents at the US patent office; 20 years ago, when they didn't have many of their own patents, it didn't make much sense to enforce foreign patents in their own country. But now that China has its own large patent portfolio abroad, it makes a lot more sense to cooperate so they can enforce these patents, too.