4DS - Anything but Charting, page-14664

US patents only apply to the US market. The largest market in the world.

China pinches IP all the time.
Corporately speaking their are standards that international business usually adheres to and as a consequence of breaking those standards a business can be punished by other corporates at large - this is punishment outside the legal system.

Also I wouldn't worry about China pinching the technology. They want to be seen as more legitimate global player and are starting to curb this behavior.
Even if they blatantly stole it no one would buy it because the US would put a sanction on any company or country that threatened it's private business interests.