They know. Often the recruiters will appeal to their affection for the ‘mother country’ and the ‘homeland’. Some of them fall for it fairly easily.
They don’t “fall for” a damn thing. WE fall for it. He should never have been here or at Raytheon.
Or they have family/relatives back in China, and are told their “health will suffer” if they don’t cooperate. Threats work well, too.