If Melbourne and Sydney had similar-sized populations and city-linked economies as Paris and London, there would not be a debate in Australia about building a high-speed rail link between them.

The merits of high-speed rail are so compelling that the project would either be near completion, or even up and running.

But the furious argument raging in The Age this morning about yet another assessment of the project, which in brief is to set aside the corridors now but build it later, raises some deeply divisive issues in Australia that cross all party lines.

Such as, how big should the Australian population be? How much money should a federation spend on projects that would enrich the south-eastern part of the continent at substantial cost to the resource-rich states, where most of the money comes from? Should government pick winners and losers in transport planning, or leave it to the market?

These are really deep and critical questions, which come with answers that will determine much of the shape and nature of the Australia in which our our children will live.

There are a long list of related burning issues. Crikey and its Plane Talking blog have fed the flames of debate about them many times in recent years, with numerous articles and linked documentation kept accessible in  online archives.

Let’s stoke the fires.  A “small” Australia will never get a high-speed rail network because it will never need one. It won’t even have enough taxpayers to sustain the maintenance of current publicly owned infrastructure or social services. It will be a mean-spirited, not-in-my-backyard, stranger-danger preoccupied country in which dementia begins to rival dental neglect as a national disgrace.

But there are future Australias that can be termed “large” and “too large”. Somewhere between the catastrophic effects of excessive growth and a miraculously well-managed “bigger” Australia — which can afford dentists, pensions, and decent transport infrastructure — the need for at least one, and perhaps many, high-speed rail corridors of various lengths will become such that they are built.

Planning for them ASAP makes sense, probably too much sense given the open space sacrifices that high-speed rail involves, in existing metropolitan zones and out in the unspoiled country.

Lower-cost air travel will also delay the viability of high-speed rail, but not prevent it.  The argument that the high-speed link cannot take more than three hours to be competitive with air is no longer valid. London will have a very-fast train to Frankfurt by 2013,  a 4-5-hour trip time that will make anyone spending at least two hours of crushing indignity at Heathrow or Gatwick before their flight even gets pushed back into the take-off queue for Germany’s commerce capital, vow never to fly the route again.

High-speed rail at current  achievable speeds of 380 kph is more than competitive with air between Melbourne-Brisbane-Adelaide, and of course, Sydney and Canberra in the middle of the matrix, provided the money to build the lines is found. The customers will not be the problem, as Eurostar between London and Paris and Brussels, or the Guangzhou-Wuhan and Tokyo-Osaka and Frankfurt-Munich lines among others have already shown.

But people have to be able to reach the high-speed stations with less inconvenience than the airports. The only way to do that is make such access a part of revitalised city transport systems, which no matter how short in comparison to a Sydney-Melbourne line, seems to be completely beyond the capabilities of the NSW and Victorian governments.

European cities, by historical accident, built the foundations of good city rail networks over a period of more than a century before high-speed rail began to proliferate. Australia has to build both, the long, fast corridors, and the short but effective commuter links, at the same time. And within an economy that is a fraction of that of the EU, and its higher population densities.

This is why the fast-rail debate forces us to consider some truly critical and far larger issues that will shape 21st century Australia.