For decades, the Australian government had a quiet, sensible rule for limiting defence spending: it assumed that the country would not suffer a major attack within 10 years.
It dropped the rule in a defence policy statement last year. Unfortunately, it had to. The rising risk of Australia having to help the US in a war to defend Taiwan against China could not be ignored. To some extent, that war could spill southward to Australian territory.
Talk of war is in many ways undesirable. But Australians have been unnerved by official warnings; they worry what a war would involve. So on Saturday, this column began looking at what a war over Taiwan, if it happened, would look like.
It would take place mostly around that island and in the western Pacific. Australian warships, aircraft and their crews probably would be sent, and be put in danger, to help the US.
Fighting could spread. China might want to attack Australian military installations, such as northern air bases and facilities for collecting and sharing information.
One would be the US-Australian facility at Pine Gap, near Alice Springs, which controls US intelligence satellites and receives information they collect. It is more than 900 kilometres from the nearest coast but, if China does not already have a type of submarine-launched cruise missile that can fly that far, one is probably in the works.
Australia's three Jindalee over-the-horizon radars are similarly far inland. If we believe the Royal Australian Air Force, these radars achieve merely the amazing ability to see 3000 kilometres, as far as Indonesia. I'm not sure I believe the RAAF, however. There are reasons, based on physics and geography, to suspect that these mighty sensors can see as far as Taiwan.
If the Chinese armed forces have a similar opinion, they would be very keen to deprive the US of the battlefield picture assembled far away in Australia. They might look at putting a missile into some critical component of each Jindalee radar, maybe its power supply.
But the job could also be done with fewer missiles, because the radars are controlled from a single facility at RAAF Edinburgh, outside Adelaide. This is easily reached by weapons from a submarine in the Great Australian Bight. Wiping out that control centre (and many of the people in it) should incapacitate all three radars. Kaput.
China would also want to shut down three installations at Exmouth, on the Western Australian coast. One, formerly belonging to the US, is the landward end of special radio communications links with submarines.
The other two, less well known, watch satellites. It so happens that Exmouth is almost dead south of a space base from which China launches many of its surveillance satellites. Soon after launch they pass close to Australia's west coast. That, presumably, is why Australia operates a radar there for determining the exact orbits of satellites, and a telescope for scrutinising them.
Northern air bases could be likely targets, because critical aircraft would probably fly from them: Wedgetail air-surveillance aircraft, tankers and US B-52 bombers. The key base in the north is RAAF Tindal, near Katherine in the Northern Territory. There are signs that the US sees victory relying partly on Tindal.
Installations might be protected by Australia's fighter force, comprising Lockheed Martin F-35 Lightnings from Tindal and, mostly, Williamtown at Newcastle. At least at first, the US would not want Australian F-35s in the main east Asian battle, because it has far more fighters than it can fit on airfields in that region.
But missile attacks on airfields in the battle around Taiwan could destroy many US and Japanese aircraft. Imagine bulldozers pushing aside the wrecks of smoking fighters. After too much of that, the US could ask for Australian F-35s. Among the many virtues of F-35s is their great range. Using them instead of other fighters reduces demand on tankers.
The US could ask Australia to send its Boeing EA-18G Growler electromagnetic-attack aircraft, but the RAAF's F/A-18F Super Hornets, which we use as strike aircraft, would probably not be needed.
Nor would the entire Australian Army. This would be an air and sea fight, except on Taiwan itself if China tried to land soldiers there, which it would do only after beating back the Americans and their friends.
As for civil life, airlines would probably fly nowhere near east Asia during such a war, but air routes via Africa and South America might remain open.
Seaborne trade could be cut, and easily. China would only have to declare a blockade and say that submarines were enforcing it. Australia and ship owners would have no idea whether submarines were there or not. Insurers would forbid ships to enter the blockade zone.
Australia's Boeing P-8 Poseidon maritime patrol aircraft would try to find submarines, aided by contacts made by other systems. The country has only 12 Poseidons and is getting two more: just 14 aircraft to cover the maritime approaches of a continent. And the US might ask for RAAF Poseidons to go north to help in the main battle, part of which would be a fight against Chinese submarines trying to sink aircraft carriers.
Then there's cyber attack. It's a murky area, with no one really knowing how much damage one country can do to another by hacking into and disrupting computer systems. Conceivably, civil communications, power, banking and many other services in Australia could be shut down, at least while engineers tried to repair them. It could go much further.
With so much uncertainty, and so much to lose, neither side might want to go down that path.
How would the war end? Most likely, one side or the other would eventually decide it was running out of aircraft, ships and missiles. Whichever side that was, China, now possessing Taiwan or firmly deprived of it, would look on the world far more malevolently than it does now.
- Saturday: Australia's armed forces are not ready.
- This article is supported by the Judith Neilson Institute for Journalism and Ideas.