Yeah, we've known that for years. But it's good that the recycling of the news this week has focused attention on our cooperation with the US in deterring a Chinese attack on Taiwan.

The pointy end of this cooperation is at Tindal, a Royal Australian Air Force base near Katherine, NT.

Tindal is in fact becoming an anchor of the US's Asia-Pacific strategy. It's not too far from China and, increasingly important these days, not too close.

If war broke out, it would surely suffer attack. The government should urgently enlarge the scope of an expansion program already underway at the base and build others elsewhere in the Top End.

Embarrassingly for Australia, the US is helping to pay for the expansion of Tindal. Since our security deeply depends on the US preventing China from taking Taiwan, and since the US is already so stressed by that task and many others around the world, we look like a bunch of cheapskates.

An ABC report this week that the expansion included six parking spots sized for B-52s set off a lot of huffing and puffing about "nuclear-capable" bombers coming to Australia.

Well, of course the upgraded base will support B-52s. It's 4,300-4,400 kilometres from Taiwan and China, so even a vague description in 2019 of planned US building work at Tindal implied the base would host aircraft suitable for such distances, most obviously bombers.

Runway lengthening and parking provision detailed by the RAAF then also showed that B-52 or B-1 bombers could be accommodated. It wasn't hard to work out what was going on.

Also, "nuclear-capable" hardly has much meaning in relation to US combat aircraft. A great many of them can carry nuclear weapons - typically smaller, "tactical" bombs. Nuclear-capable US aircraft routinely come to Australia.

B-52s have turned up here from time to time over many decades. The importance of the expansion at Tindal is that the base will now better support them and other US combat aircraft, plus aeroplanes used for refuelling and surveillance.

The B-52 is the widest of those various types, so sizing parking spots for it just means the spaces will take any of them.

Nonetheless, B-52s and other bombers would be among the most important aircraft that the US would send to Tindal in a crisis and operate there in a war - with Australian permission, which would surely be granted. The planes won't be based there permanently, however.

The main B-52 mission would be carrying missiles thousands of kilometres north to threaten Chinese ground installations and ships. China would have to take that capability into account in considering whether to attack Taiwan, so, by improving Tindal, Australia and the US are helping to prevent war.

A big factor behind base location, and many other military issues, is the relative cost of weapons. One thing that strongly influences cost, and therefore a weapon's abundance in an inventory, is range.

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We don't see the US lobbying South-East Asian countries for much base access partly because they are just too close to China, within reach of ground-launched strike missiles that don't need to fly far and are therefore cheap and numerous. China's fighters and fighter-sized strike aircraft, abundant compared with its long-range bombers, can also reach a lot of South-East Asia.

So any US air bases there would soon be pummelled in a war.

Some bases in Japan are also in range of many relatively inexpensive Chinese missiles, though others are fairly distant.

It was obvious last decade that the US needed more locations from which it could project air power on this side of the world, especially places that were more than 2000 kilometres from China yet not too far to be useful. Tindal is becoming one of them.

Though far to the south, it would still be hit in a war, but China would spend most of its finite long-range strike capacity on targets of greater importance. For example, China would need to attack northern Japanese bases and the massive US facilities on and close to Guam, far out in the Pacific. Distant US warships would be priority targets, too.

Attacks on Tindal would use either big and therefore scarce ground-to-ground missiles or, more likely, bombers launching cheaper weapons over Indonesia or the southwest Pacific. Forthcoming stealth bombers may be able to get much closer.

Even after the expansion, Tindal will have just one runway and a few taxiways. It needs more of both, plus other redundant features and tough shelters for aircraft, to make it harder to knock out of action. If it is to be an anchor of US and, indeed, Australian strategy, we must spend to make it survivable.

Also needed is urgent construction of additional Top End air bases, which would be close enough to each other to provide mutual fighter cover.

More bases mean more places to which bombers, tankers and other vital aircraft can disperse, sustaining air power even as some locations suffer attack.

We also need more upgrades of air bases that we already have. RAAF Darwin may be unsuitable, because it's surrounded by urban development and therefore civilians, but bases on Cape York Peninsula and on the northwest coast of Western Australia should be expanded and toughened as quickly as possible.

As with so many things in Australian defence policy, this obviously urgent action should have been taken years go. Yet it's not happening even now.