Under Pax Britannica, merchant families often sent one brother to Singapore, one brother to HK, one brother to Malaya and one brother to India or China. This is why we have a Har Par Villa in HK and in Singapore; Sin Chew Jit Poh newspapers in Burma, Malaysia, Singapore and HK; Shaw Brothers cinemas in Malaysia, Singapore and HK. The Sassoon name can be found across Calcutta, Singapore, HK. The British city ports were all a fluid single "country" in those days, so HK and Singapore very much were twins at birth and our first 100 years of history.

Malacca and Penang had their handover to the mainland much earlier in the 50s and ceased to be city states. Around the world, other city states faced mass extinction in the wake of the two world wars until there are only two handfuls of city states left today : the Vatican, Monaco, Singapore, Macau, Hong Kong, Qatar, Malta, Brunei, Kuwait, & Bahrain. Of these only Singapore and HK have meaningful populations - the rest have <1mm citizens. Hence we are closely related as political entities, especially so since we are both majority Chinese. We are geopolitical twins.

As twins we in Singapore understand better than most the true difficulty in HK's desire for sovereign independence.

We have learned the hard way:
1) of the need to raise an army through conscription to achieve self-defence, because city states do not have enough population to do otherwise,

a) of the serious challenge of convincing all parents you need to take their sons away for the military

b) of the extreme and painful lengths necessary in order for conscription to be fairly applied. The natural tendency is for the rich and powerful to seek exemption, which even a marginally bigger country with 20mm people can get away with but not a city state.

2) of the city-state's perennial struggle with water. Like Singapore, HK has too many people to depend on local reservoirs and relies on water supply from the mainland. This is a permanent knife on our throats which is why we need an effective army to enforce the supply contract. Waiting for the ICJ to rule in your favour doesn't help you perish from thirst. And the ICJ cannot enforce a ruling. It doesn't seem likely HK can ever force PRC to honour a water supply treaty. Without water, even a democratically elected HK prime minister will always wear Beijing's leash.

So we know even if China gave HK independence without a bloody civil war, which would itself be a pipe-dream, HK would only be reborn as a cripple state, at the mercy of being squeezed every year either on water, food or electricity (HK imports 25% of its electricity from the mainland).

HK will need to radically overhaul its mentality and devote a huge chunk of GDP and land towards defence which unlike Singapore it currently spends zero. 20% of our precious land is set aside for defence, but the bigger price is the human commitment of all males from 18 to 40.

It will need 20 years to build up the local skill base to operate and staff a modern army, air force and navy. And finally it will need to forge the strength of national unity and character it takes to pull everyone to make those sacrifices that we went through from 1965 to 1985.

We are geopolitical twins with similar constraints and considerations. And that is why we understand HK possibly better in some ways than it understands itself in this desire for sovereign independence. As a city state on the doorstep of a power it cannot best, cooperation and subjugation is the likely outcome, the way that France exerts significant control over Monaco.

A post-script about British rule in HK:

In 1985 Portugal was applying to join the EU. The UK found Portugal was planning to give Macau residents Portuguese citizenship before handover. Because the UK had no intention of giving HK residents UK citizenship, the Foreign Office put pressure on Portugal to drop their plan for fear it would reflect poorly on the UK and force them to do the same. They also feared HK citizens might claim Portuguese citizenship through Macanese links and settle in the UK through Schengen.

Portugal refused to comply and issued citizenship to Macau. As a smoke screen, the UK decided to create a British National Overseas passport for Hong Kongers, a document which only confers 6 month visa free stay in the UK, falling quite short of what it says on the cover.