[vmlinuz]

So I'm not going to get into an argument, just make three basic points to reply here:

Hong Kong did not always belong to China, and was not leased to the UK - part of Hong Kong's area (the New Territories) was leased, but Kowloon and Hong Kong island were ceded in perpetuity.

China signed an international treaty with the UK regarding the handover of Hong Kong, a treaty which comes with certain rights and responsibilities. Sure, there's no real way to actually enforce such a treaty, but you can't really complain if other countries react to the breaking of a treaty with punitive measures, and don't trust the treaty-breaker not to break other treaties in future.

How about asking the people of Hong Kong what they want? There's about 7.5 million of us here, with a fairly unique history and culture, so maybe just being subsumed into another country wouldn't be the choice of the population?