The defence review, announced on Wednesday, will be critical for the security of this country, maybe even its survival as a fully sovereign nation. If review leaders Stephen Smith and Sir Angus Houston don't recommend a massive overhaul of the armed forces, they won't have done their job.

But we face risks already. Even as you read this, China is completely surrounding Taiwan with military force in response to a visit to the island by US House of Representatives Speaker Nancy Pelosi. Amid such aggression, the chance of war by accident is alarming.

So, consider that some improvements to our armed services, mostly the air force, are obvious and urgent. They don't need to wait for a review.

Start with airbases. The air force has six forward bases, the ones we'd use in a war, ranged across the north of the country from Exmouth, WA, to Townsville.

Two on the WA coast and one on Cape York Peninsula have no rail access. How would they be supplied with fuel in a war?

The traditional answer is "by ship" - as if a tanker plodding near a coast would survive against half-decent air power.

Yet an airbase without fuel is useless.

Marles needs to demand multiple alternatives to shipping and promptly implement more than one of them.

Most obviously, we must identify civilian tanker trucks and willing drivers (in large numbers). Perhaps fuel can be supplied by requisitioned airliners (flown by whom?). And a costly answer would be a pipeline to each base.

Can the air force rapidly repair a forward base after its concrete is cratered by a heavy salvo of strike missiles? Little information is available, but my bet is that the capability, being much less interesting than aeroplanes, is rudimentary.

Scores of construction vehicles are probably needed, including surplus ones for when some are destroyed. Such material as quick-setting cement needs to be stockpiled on site.

Marles doesn't need a review before attending to this. He just needs to ask a few hard questions and, almost certainly finding the air force's answers inadequate, order a response.

Aircraft are even easier to smash than runways. Our bases don't have tough shelters for our $240 million F-35A fighters.

Admittedly, there is some doubt that hard shelters are good enough against modern warheads, but clever new designs have appeared and they would at least improve the chance of aircraft survival.

Marles should also order construction of airbase bunkers for personnel, more storage for ammunition, and lots more fuel tankage.

One answer to vulnerability is redundancy: having spare stuff for when some is smashed. So we need more concrete: not just one runway and a parallel taxiway for each base, but several of each.

Altogether, our forward airbases are flimsy, fine for the days when we worried about only Indonesia, but hardly a match for the Chinese air and rocket forces.

They're also too few. They're generally 900-1200 kilometres apart, too far for effective mutual support - for example, when one, struggling to recover from missile strikes, needs fighter cover from its mate. We should prepare now to build more forward bases.

Top End civilian airfields and stretches of highway can be redundant bases. We need arrangements for getting fuel, weapons and ground crews to them so they can suddenly spring to life as points of airpower.

Marles also needs quick answers and decisions on the robustness of navy bases. Would six well-aimed cruise missiles cripple one for a month?

Now for the shiny stuff - equipment. Weapons and everything needed to make them operational costs a lot and must be bought with care. But, again, some decisions are really easy.

Marles cannot go wrong by promptly placing an order to double the size of the Airbus A330 tanker fleet to 14 aircraft, preferably by modifying cheap second-hand airliners.

Nor can there be a mistake in doubling the planned force of 14 Boeing P-8 Poseidon anti-submarine, anti-ship and surveillance aircraft, which are highly suited to the maritime war we must worry about.

MORE AGE OF THE DRAGON:

Ordering 35-40 more F-35s today, adding to the currently planned 72, would never be a cause for regret.

If there is a reason to pause for thought about fighters, it is that we should consider the F-35B version, which takes off in a very short runway length and lands vertically. It's ideal for sustaining airpower at a shattered base.

All these easy equipment decisions are for buying more aircraft of types that are in service and in production, so additions would be quick, economical and dependable.

As for the navy, almost everything it does in equipping itself takes more than a decade, so no great short-term boost to its capability is achievable, and there is not much point in trying to hurry it up by seven months.

Except in the transcendentally important area of nuclear submarines.

As this column has repeatedly argued, we should take a risk with some money and order parts immediately for Virginia class submarines even before the US agrees to let us use them - then build them all in America.

Money for the air force and navy can come from cancelling army programs.

Our army has failed to make itself relevant to the China threat. We can regard it not as a contributor to national defence but as a pot of money for paying for things that are.