There is a certain irony about Macquarie Bank warning against new financial regulations, when only six years ago it was begging the government for help, writes Ian Verrender.

Q. What are the two greatest weapons in a businessman's arsenal?

A. Chronic memory failure among the broader community and a compliant business media.

Macquarie boss Nick Moore used both to full effect last week when he issued a dire warning to David Murray, the man heading the inquiry into the future of Australia's financial system.

Think twice about imposing new regulations on our banks to protect taxpayers from a collapse, Moore warned. Such regulations could backfire and cost the nation dearly.

Ah, the irony! Accompanying the piece was a snap of Moore, half smile playing at the corners of his mouth, elegantly coiffed and adorned with a powder blue tie that perfectly complemented the mosaic background of the Macquarie boardroom.

Missing was any hint of the frantic desperation of six years ago as Macquarie careered out of control, under siege from an army of steely eyed traders betting the bank would go down.

The panic took hold just a few hours after the collapse of Lehman Bros on September 15, 2008. What did Moore and his executives do? They went begging for help.

Freedom of Information requests by Sydney Morning Herald reporter Michael Evans and your correspondent back in 2010 uncovered a deluge of emails to federal government ministers, Treasury officials and the corporate regulator that began almost immediately after Lehmans imploded.

But you'll never see or read the juicy details. They've been suppressed.

According to Treasury, should the contents of those emails or meeting notes ever come to light, they "could reasonably be expected to adversely affect the Macquarie Group". Heaven forbid!

What we do know is that the pleadings were devilishly effective. Within days, the government shored up offshore Australian bank debt with a taxpayer guarantee. And the corporate regulator banned short selling of Australian banks, a move that staved off the short selling attack.

Macquarie was saved. And so began the myth that the Australian financial system somehow was better and stronger than the rest of the world, that it alone survived the great global financial crisis where all others failed.

It is a myth now being employed as a dangerous argument as to why Australian banks should not be subjected to the kind of controls now being considered by global regulators.

David Murray, the former longstanding boss of the Commonwealth Bank, has been examining ways of shoring up the system in the event of a repeat of the 2008 financial system meltdown.

In recent weeks there have been hints Murray may recommend regulations that would require our banks to hold vastly more cash as a buffer against the kind of financial maelstrom that erupted in 2008.

On cue, the chief executives of every major Australian bank have promptly beaten a path to Murray's door. Profits would be restricted, share prices crimped, credit rationed. Australians would suffer, they've cried.

Macquarie's brush with death is precisely the situation Murray now is attempting to save the nation from ever being forced to confront again.

At the very least, he wants to ensure taxpayers never have to foot the bill or put the nation's collateral on the line.

It may not have been the biggest Australian bank. In fact, from a retail perspective, it was relatively minor. Globally, however, Macquarie was the nation's financial flag bearer.

Its satellite infrastructure groups owned everything from London's water supply to North American toll roads, a suite of international airports, ports in Poland and every conceivable kind of infrastructure from South Korea to Southampton.

Moore helped create what became known as the "Macquarie Model", a structure so admired for its capacity to generate wealth during the boom that Wall Street's mightiest institutions belatedly set their minds to emulating it.

Its genius was that the Macquarie mothership seemingly was impregnable. All the debt and risk was loaded into its myriad satellites, Macquarie Infrastructure, Macquarie Airports. The list went on.

But when the attack finally came, the defences crumbled. Investors cared little about the distinction between the parent and the satellites and sold everything named Macquarie.

The bank's share price plunged from about $98 to $15.75 as short sellers attacked what they believed was a mortally wounded beast.

Macquarie's then chief financial officer Greg Ward always claimed the bank had adequate funds and was never in danger of collapse. It's a cute argument. For it ignores the fact that banking is the most dangerous and highly leveraged business on the planet. It relies on confidence. And when that evaporates, banks collapse.

Ironically, Moore and his cohorts debated giving up the group's banking licence as the noughties boom gathered speed. It was too restrictive, they argued. Fortunately, it was kept. And ultimately, the licence proved the difference between Macquarie and its mini-me, Babcock & Brown, which ended up torching close to $10 billion when it flamed out.

Macquarie wasn't the only Australian bank in danger. All of them were in trouble. While only the National Australia Bank was caught with the kind of toxic assets that brought Wall Street to its knees and had banks across Europe reeling, Australian banks were on the other side of the trade.

That didn't mean they were immune. That plugged them directly into global banking and the crisis that came with it.

From 1990 on, our banks raised huge amounts of cash from offshore wholesale debt markets, imported it and lent most of it for mortgages that elevated Australian housing into the stratosphere.

Foreign private debt has risen to 86 per cent of GDP, from less than 30 per cent in 1989.

As economists Ross Garnaut and David Llewellyn Smith wrote in their book, The Great Crash of 2008, that reliance on offshore funding rendered multiple Australian banks insolvent when credit markets froze.

The banks simply couldn't refinance their short-term debt obligations. Forget the revisionism fashionable within finance circles now, that's what you call solvency problems. And make no mistake, Australia's banks were bailed out by taxpayers.

Between them, they borrowed more than $120 billion under the taxpayer AAA guarantee with Macquarie accounting for about $20 billion. They now make a song and dance about having to pay a fee for the privilege – as though bank fees somehow are a foreign concept.

How safe is our banking system? Not as safe as you might think. Certainly, not as safe as our banks make out.

Mortgages on overpriced Australian real estate accounts now total about $1.3 trillion, 40 per cent of that sourced from offshore debt markets.

According to ratings agency Moody's, mortgages account for about 65 per cent of all bank loans. Hardly what you'd call a diversified portfolio.

The big four banks have employed a neat trick since 2008 when they were allowed to set their own risk weightings for loans. Risk is a key factor in determining how much they should put aside in reserves to cover bad debts.

You can increase reserves either by putting aside more cash. Or you can lower the risk weighting. Guess which option our banks went for?

It is a problem not lost on Murray who, along with global regulators, has hinted he may opt for a simpler mechanism to ensure they have adequate reserves so investors rather than taxpayers wear the pain in the event of a collapse.

No wonder bank executives are worried.

Australian bankers are among the most highly paid executives in the land and Macquarie's Nick Moore is top of the pile. It could have been a different story if the 2008 lobbying campaign, and the later rewriting of history, hadn't been quite so successful.

Don't expect anything less this time around.

Ian Verrender is the ABC's business editor. View his full profile here.