As for HK, the UK government was stupid for not negotiating a better deal and installing a strong democratic frameworkk in the first place. It should have stayed under British control, it would have been much better. As for Heathrow, that is a difficult problem, there is the NIMBY factor and environmental concerns like noise and traffic problems that need to be addressed by democratically elected governments, or they will face a possible electoral backlash. It is the same in my home town Sydney with the new airport at Badgery's Creek finally approved. In the UK or Australia politicians can't ride roughshed over peoples rights. Projects can take longer to proceed in Western countries than in dictatorships like China because there are many checks and balances that need to be taken.

About HK, quite right, OK it had to be returned because all the water and other stuff was coming from China, and maintaining a rump colony of just hong kong island and kowloon would not have been economically viable, but it is one of many many mistakes we have made in foreign policy. Like pulling out of the gulf (trucial states) and leaving the gulf arabs there without defense, then the Americans went in and got the lucrative oil and gas contracts, and we got nothing, despite defending them and helping them form their country in some way, the present day UAE. A huge mistake of the labour government, we could have controlled the place by proxy, and had access to the oil and gas, all in return for keeping it as a protectorate.

http://www.thenational.ae/news/uae-news/sun-sets-on-british-empire-as-uae-raises-its-flag#full