Something momentous in the development of Australia-China trade connections this Thursday has so far slipped under the media radar.

It is the launching of thrice weekly non-stop jet flights between Sydney and Shenzhen with continuations to Hangzhou by Hainan Airlines.

Forget the hoop-la about Hainan as an airline.  These flights to supposedly secondary China cities are a door swinging open on business opportunities on a prodigious scale.

The combined greater metropolitan populations of these “smaller” cities is 21 million, or just under Australia’s total population and if anyone has any doubts about where the money is, business travellers familiar with the region will urge you to just do the trip between Hong Kong and Shenzhen amid the hordes of commuters and shoppers any time your border permissions are in order.

The modern metro systems of both cities, which are far, far better than anything even planned in Australia, meet, for want of a better word, on the opposite banks of the Shenzhen River, which is crossed by a pedestrian overpass.

If you are a regular Hong Kong worker or shopper, you use an efficient biometric and thumbprint-scanning system to make the border crossing that is just a minor interruption to a rail commute.

But if you are a foreigner entering Shenzhen, which is right in the heart of China’s Pearl River delta manufacturing and textile exporting domain, it’s the pits.  Especially after making the flight to Hong Kong.

That access and time wasting hassle is bypassed by the new flights.

Shenzhen is the first “special economic zone” set up in China. It was a fishing village in 1977.  Today it is an all new architecturally stunning city of well spaced skyscrapers, and economically  “loaded”. There are serious discussions on both sides of the Shenzhen-Hong Kong border of a merging of the cities, and of course, some very serious human rights and political freedoms issues to be resolved, but the fact that there is a discussion is of itself significant.

Hangzhou, which will also be the start and finish city for the A330-200 flights, is slightly closer to Shanghai than Canberra is to Sydney, not that you will easily detect where each begins and ends travelling between them.

After Shenzhen and Hangzhou, expect flights to such “secondary” cities as Wuhan and Tianjin to follow, and for all of them to go multidaily to the major Australian cities as the deluge of air links begins, just one of the many consequences for the world of 1.3 billion people making a long march to their place under the sun.