But that's exactly my point. HK dollars can only be a global currency if China back it, by using it to settle foreign trade. Whether HK can be a gateway to China or not depend on China's political will, the same for HK dollars. By using HK dollars to settle foreign trade, China can propell HK dollars to a new height, and China can also create a buffer for yuan, and China doesn't need to let go of capital control for yuan.

I never said my original plan is for China to have cake and eat it too. It is actually the other way around. I'm asking whether China can globalize yuan without letting loose the capital control? Wanting that is what I meant as wanting to have cake and eat it too.

Backing HK dollars as Chinese currency for international trade, yuan will probably never be a global currency, it will only be used in domestic, but HK dollars can be a global reserve currency, and as long as China "own" HK, China will also own the influence that come with it. Needless to say, if China want to implement that, it also need to depeg HK dollars from USD, to prevent it from US control. Of course if China want to let go of capital control, it is a whole different scenario altogether. But absent of lossening capital control, I just can't see how China can globalize yuan. Moreover like I said before, I'm not sure if letting go of capital control is a wise choice, especially if Chinese financial market is not yet competitive. HK financial market on the other hand, is ready.