AAP/Alan Porritt

The news that Australia is about to spend $24 billion on a new generation of fighter aircraft has been greeted with remarkably little critical comment or analysis. It is hard to imagine that any other public policy initiative on this scale would have been greeted with quite such equanimity.

But when the defence of the nation is at stake, no-one wants to risk looking like an unpatriotic strategic illiterate – especially on Anzac Day.

It is, however, possible to make two predictions with some confidence. First, if history is any guide, the budget for these planes will inevitably blow out. As yet unresolved technical difficulties with the supposedly state of the art Lockheed Martin F35 Joint Strike Fighter almost guarantee this. Canada and Turkey also look like pulling out of the project, pushing up the cost for other buyers.

The second prediction is this: it is as near to certain as anything can be that they will never be used in anger.

This is a good thing, no doubt, and the plane’s admirers will no doubt claim that this is testimony to its deterrent effect. But would things have been different without the new fighters and the eye-watering outlay they involve at a time of alleged austerity?

Strategic hard heads and technical experts, of whom there seem to be no shortage at such times, will claim that national security is simply too important to be left to chance, and no price is apparently too great to pay in ensuring it.

And yet, this is not quite as axiomatic or self-evident as they would have us believe. Not every country subscribes to this logic or feels as impelled by what Edward Luttwack describes as the “the Anglo-Saxon trait of bellicosity”.

New Zealand, for example, has not only been expelled from the ANZUS alliance with Australia and (more importantly) the US, but it has essentially abandoned the idea of having an independent and effective air defence capability altogether.

Does anyone seriously think that their security has been materially diminished as a consequence? Are hostile powers queuing up to invade and take advantage of its weakened state? Hardly.

Successive New Zealand governments have made the entirely rational calculation that they are a small nation, a long way from potential areas of conflict, with limited national resources that might be better directed toward national development rather than defense.

Even if argument is made that New Zealand somehow freeloads on the back of Australia’s military spending and benefits from the defense of its supposedly vulnerable north, does this make their calculation of their particular national circumstances and interests any the less rational or wise?

Australia is not New Zealand and a different strategic calculus potentially applies, but is it one that merits this sort of expenditure and this sort of equipment? In what possible circumstances could the possession of 70 or even 100 F-35s make a decisive difference without which Australia’s national security would be unambiguously compromised?

Would contributing to a regional arms race really underwrite our long-term security or would it actually make conflict more likely, as the timely example of World War One reminds us?

Plainly, no-one is thinking about invading Australia. As has been frequently noted, only the US has the capacity to do so in any foreseeable circumstances, and they are actually “invading” as a consequence of enthusiastic bipartisan invitation. In this regard, the hard heads are undoubtedly correct: with American bases in Australia the already remote possibility of foreign aggression toward Australia becomes even less likely.

So if there is widespread agreement that the defence of Australia is not at stake, why the need for such (potentially) lethal fire power? The logic underpinning Australian strategy revolves around the alliance and the need to “do our bit”.

Given that the US is planning to buy something like two and a half thousand of these planes, Australia’s contribution to any military effort will, as ever, be largely tokenistic and make no difference to the outcome of any actual conflict.

Much the same could be said about the equally ruinous proposed expenditure on new submarines. But whether we buy 12, 20 or 100, it is worth thinking about the precise circumstances in which such weapons systems would make a decisive difference or change the behaviour of potential adversaries.

Playing up the possible benefits to Australia’s beleaguered manufacturing sector is a bit rich from a government that normally has no time for industry policy, but it is, at least, a potentially tangible benefit. The same can’t be said about their ostensible strategic rationale.

Tony Abbot has justified this massive expenditure on the basis that we “don’t know what may be around the corner”. Actually, we do. It’s called climate change and it’s coming to a country near you - with potentially apocalyptic consequences for our collective security.

If the government really is serious about addressing clear and present dangers, this might be a good place to start. $24 billion is just the sort of money that might help to underwrite our long-term economic and environmental security.