Who formulated the principle that involves the country that is hostile to "mainlanders"?
Hong Kong–Mainland China conflict:  Increasingly, these tensions have resulted in a rising sentiment in Hong Kong of hostility to "mainlanders" and resentment at a perceived trend towards assimilation and interference from the mainland and the central government, and at the same time a rising sentiment in mainland China of bewilderment and resentment at assertions that Hong Kong is, and should remain, different from the mainland in terms of political system, culture and language.
i don't know