Still no inquiry. Still no answers. A trillion pounds has been devoted over the past 18 months to protect Britain's financial system from alleged Armageddon, with not a murmur of value for money. This stupefying sum is more than has ever been spent on any project by any government in British history.

We know where the money came from but we do not know if it was necessary, nor who now has it. We know only that, a year on, Britain is experiencing a worse recession than any comparable country. The lack of accountability, the sheer lack of curiosity from the political community, is amazing.

The nearest to an explanation came from the man responsible, Alistair Darling, on Michael Cockerell's recent BBC documentary on the Treasury. If he had not acted in October 2008 as he did, Darling asserted, "the bank doors couldn't have opened, cash machines wouldn't have functioned. All over the world people wouldn't have got money". Who says?

The reality is that at the time, a year after Northern Rock and with Lloyds/HBOS and RBS faltering in the wake of the Lehman Brothers collapse, Whitehall was in policy turmoil. Every option was in the air. Darling and his patron, Gordon Brown, were in perpetual conclave with advisers such as Lord Myners and Lady Vadera and Downing Street's "UBS mafia". Calls were coming from important City figures saying such things as, "We can't go on beyond lunchtime … Give us the money".

Faced with a global asset bubble of some $290 trillion about to burst, a frantic Darling started throwing millions, then billions, then a trillion at underpinning the banks' near worthless "casino" debts. He never spent such money on indebted homeowners or indebted manufacturers or indebted African states. He did it to banks because they told him they were too big to fail. Advised by bankers, surrounded by bankers, obsessed with bankers, Darling paid.

I would like to know why. Ask those involved and they go wide-eyed and mutter "Armageddon", rather like Tony Blair explaining the Iraq invasion. To these people, not letting banks fail was not an option but a creed. They cannot explain what is "wrong" with taking hold of a reckless bank in trouble, guaranteeing its deposits (and cash machines) and continuing to lend against a Treasury guarantee, while dumping the casino activities into administration. Shareholders lose out, but that's capitalism. Talk of bank doors closing is rubbish.

Andrew Ross Sorkin's Too Big To Fail, the chaotic but gripping saga of September 2008, tells of Wall Street and Washington playing with the "good bank, bad bank" option over and again. At one point Lehman's toxics were to be hived off into a SpinCo (dubbed ShitCo by Wall Street). It did not happen, but a version was tried at AIG. In Britain in 2007, Northern Rock was both nationalised and reorganised on a good bank, bad bank basis. The good bank reported this week, and should soon repay the taxpayers their investment. The policy worked.

So why were RBS and Lloyds/HBOS not fully nationalised, rather than given unconditional largesse? Speaking at this year's Spectator lunch, Darling boasted that "I own four banks". They appear to own him. They assured him they would use his money to lend to businesses and homeowners to avert recession. They lied and Darling knew it. He knew his money would disappear into underwriting the banks' casino debts and overheating the stock market.

By December 2009, a year after the bailout began, bank lending was not stagnant but declining at an unprecedented rate. Still Darling did not relent. Indeed he made lending harder by increasing VAT, reducing high street demand and rendering commercial lending more, not less, risky. Meanwhile the Bank of England poured cash into bank balance sheets. An Economist headline put it pithily: "Banks fine: pity about the customers."

Darling did not even require banks to curb their extraordinary bonuses, even when they consumed a large share of reported losses. The American financier, Warren Buffett, famously protested that banks were "being run for their employees… with lucrative paydays that enriched people who are not particularly intelligent and add little value". Since he claims to own them, Darling might at least explain why he was further enriching them at public expense.

Last year John McFall, the Labour chairman of the Commons treasury committee, argued for a "state bank". There were four already, but economically inert. When RBS returned to the casino tables, the money it spent was draining from the real economy in Darling's repeat of the Thatcher/Howe recessionary squeeze of 1980-81. At a time when consumer demand was collapsing, the government found itself unable to respond with more VAT cuts, pensions bonuses, higher social security and more public projects, in other words a classical Keynesian answer to a slump.

That is what Germany and many far eastern countries did, with benefits rises, tax holidays and consumer scrappage schemes. The British government did the opposite. It ended such schemes, increased VAT and made deep cuts in government (which means also private) spending. Small wonder one in four high street stores might be facing closure – but no more banks. Darling continued to claim that his printing of new money through quantitative easing was aiding business. Yet each week the financial pages reported how the extra money was evaporating, most of it disappearing overseas. It would have been better to adopt the old monetarist answer to recession, of dropping bank notes on shoppers from helicopters.

I appreciate there may be arguments against this analysis, but it would be good to hear them. Why did Darling not let HBOS or Lloyds fail, merely guaranteeing their deposits? Alternatively, why did he not nationalise and split up the ailing banks in October 2008? Again, if they really were too big to fail, as they alleged, why has he not made them emphatically smaller, so when they fail next time they do not drag the economy down with them?

Gillian Tett's book on the psychology of credit greed, Fool's Gold, shows the corrupting effect of unfettered derivatives trading on the whole financial system. Darling has done nothing to mitigate that effect. The world is alive with talk of curbs on bonuses, hedge funds, short trading, proprietary dealing and transaction taxes. There is talk of stress tests, living wills and higher reserve ratios. In almost all these arguments, Labour ministers are on the side of unregulated banking and against further controls. They are the wildest of free-marketeers. Brown and Darling have gone native and become puppets on a banker's string.

Britain has paid, and will go on paying, a horrific price for this government allowing bankers to dictate credit policy after 2008. To avoid ministers suffering the ideological odium of proper nationalisation (as opposing to bailing-out), Britain is being forced to lose jobs, firms, infrastructure, prosperity and the happiness it brings.

Too big to fail has taken a savage toll on the economy. If it was worth it, I would like to see the account. If not, someone should pay. Yet because the policy was backed by all three main parties, there is no questioning, no inquiry. All is silence.