This video makes a compelling argument that the purpose of the current HK unrest is to move investments out of HK and into the US.
If this is true, then China has two options:
1. Stop the move. This can only be done if China restores order in HK and, more importantly, restores investor confidence.
2. Offer a more attractive destination. If China can convince investors that they should move their money out of HK and into China, then China wins and the US loses, badly.
I think option 2 has been Beijing's plan all along, and it's what I wasn't seeing before. Sending the PAP into HK creates political uncertainty against China itself, and would be counterproductive to this plan.
If this is indeed how things are playing out, I am, unfortunately, not optimistic about HK's future. If China and the US is engaged in a tug-o-war for HK's investments, then regardless of who wins, HK will be finished.
HK's only hope is for China to win this tug-o-war, because if the US wins, it will not care one whit about HK. If China wins, then HK will be given the chance to rebuild.