The uncovering of an alleged plot involving the Khayat brothers to bring down an airliner or launch some sort of toxic gas attack in Sydney should prompt a serious rethink about how effective we are at protecting ourselves from terrorism and why we’re spending so much money doing so.

If police allegations and leaks from within security agencies are true — and we have previously seen lurid charges of terror plots levelled against individuals either proven to be wrong or wildly overstated before — the poison gas attack appears to have been wildly ambitious, but the plan to bomb an Etihad flight, using another of the brothers as an unwitting mule for a bomb, was only a couple of steps from succeeding. 

Crucially, one of those steps involved successfully getting the bomb through airport baggage screening; according to media reports a number of subsequent efforts to test if the device would had got through screening all succeeded in spotting it. Otherwise, it was plain dumb luck that prevented the deaths of hundreds. The other big question, apart from whether the device would have been caught, is how military-grade explosive was able to be sent by normal air cargo from Turkey to Australia, and then make it through Customs.

What does this tell us about how effective all the money we’re spending on making ourselves safe from terrorism is?

According to the government two years ago, it was “investing $1.2 billion in new funding for national security in the 2015 budget, building on the $1 billion in funding we announced in the 2014-15 MYEFO”. The funding included money for Operations Okra and Accordion, the military operations to bomb Islamic State and train the Iraqi army. In the 2016 budget, the budget papers show the government allowed for an additional $671.6 million in national security spending, most of it on Okra and Accordion. In the 2017 budget, Okra and Accordion received funding of $650 million (plus additional funding in the out-years), and there was another $30-odd million in funding for the AFP and other security agencies.

[The real threat of terrorism to Australians, by the numbers]

The total in extra national security spending since 2014 is thus $3.55 billion or thereabouts, according to the government’s own statements. To give an idea of how much money that is, look at how much money the government says a human life is worth. According to the Department of Prime Minister and Cabinet’s “guidance on how officers preparing the cost-benefit analysis in Regulation Impact Statements should treat the benefits of regulations designed to reduce the risk of physical harm” (thanks to Michael Pascoe for the tip), the cost of a human life is officially $4.2 million in 2014 dollars, or $4.32 million in current dollars.

To put it in cost-benefit terms, our security agencies, and the bombing of Islamic State, would have to save around 890 lives to have been worthwhile — according to the way the government itself calculates the costs and benefits of policies. Of course, terror attacks come with economic consequences as well, although events have to be of 9/11 scale in order to have noticeable impacts on GDP. But even factoring in a couple of billion dollars in economic costs from thwarted terror attacks still makes that additional $3.55 billion questionable.

Both the head of ASIO, Duncan Lewis, and the Attorney-General, George Brandis, have recently said that security agencies have thwarted a dozen terror attacks since 2014. A media report says police claim to have thwarted not 12 but 15 terror attacks. The alleged attack by the Khayat brothers would have been the 16th, and by far the deadliest — costing hundreds of lives. But as it turned out, that attack wasn’t thwarted by agencies, and only uncovered thanks to foreign intelligence.

Do 15 thwarted attacks — most of them planned to be small-scale attacks using ready-to-hand tools like knives and vehicles — mean the extra funding was worth it? Not necessarily. We already spend more than $35 billion a year on national security, defence and law enforcement, according to the 2015 budget. The extra spending since 2014 has been only a small addition to the money we were already giving to defence and security agencies — the billion-dollar plus annual budget of the AFP, for example, and the half-billion budget annual budget for ASIO. And the Commonwealth is not the only counter-terrorism actor — state and territory police forces are involved as well. Indeed, some of the thwarted plots related entirely to state and territory police. How many of the 15 attacks would have been thwarted if resourcing had stayed exactly the same as it was in 2014? Probably all of them, certainly most of them.

So how much extra security has that $3.55 billion given us?

The answer appears to be: not a lot. When Tony Abbott announced in 2014 that Australia would join the bombing campaign against Islamic State, he explicitly linked it to domestic security as well as foreign policy. “This is about taking prudent and proportionate action to protect our country and to protect the wider world against an unprecedented terrorist threat,” he said. But now — as always appears to be the case with the War on Terror — we’re being told by security experts that the defeat of Islamic State has done nothing to reduce the threat to Australia.

[Keane: why the War on Terror gets a blank cheque but we ignore bigger threats]

In fact, like every other Western military intervention in the Middle East, it has likely made us less safe and more likely to be a target of terrorism — as security and intelligence officials have long stated, and as voters themselves believe.

In fact, there’s no evidence that that $3.55 billion has made us in any way safer, and it has possibly made us less safe. And this isn’t some academic exercise: that $3.55 billion could have been used for other purposes — put into our health system, spent on our roads, used to make dangerous occupations like farming safer, directed to mental health, even spent helping our police forces by getting more guns off the streets. Lives could have been saved with it — perhaps many more lives than were saved through thwarted terror attacks.

And there’s no means to properly investigate this. Parliament’s Joint Committee on Intelligence and Security has no power to inquire into, for example, why it might have been mere luck that saved hundreds of lives. Even under the changes proposed by the recent L’Estrange-Merchant intelligence review, the committee would still be prevented from conducting any “operational” inquiries, even in camera.

To raise the cost of national security spending, and suggest it may not be worthwhile, is to immediately elicit accusations of being indifferent to loss of life, and of seeking to minimise the terror threat, which occupies a special place for both the media and politicians as a barbaric and random death at the hands of an evil Other. Politicians say that their first responsibility is to protect their citizens. Indeed it is. But policymakers, every day of the week, make decisions about how to use taxpayers’ money in ways that save or fail to save lives, and counter-terrorism is no different to other areas of policy that have life-or-death consequences. And the events of the last week suggest we’re spending a lot of money protecting not very many of us, when it could be saving many more lives elsewhere.