The most audacious monetary experiment in modern history ended on April Fools' Day. America must walk without crutches, on gangrenous legs.

By Ambrose Evans-Pritchard

April 4, 2010 - The U.S. Federal Reserve has completed its purchase of $1.7 trillion (£1.1bn) of mortgage securities, agency debt and U.S. Treasuries, the conjuring trick of "credit easing" that allowed Ben Bernanke to create stimulus equal to 12% of Gross Domestic Product.

The Fed's money creation has been more or less the size of Washington's borrowing needs for the last year, as Beijing notes with suspicion.

We will never know whether it was wise to go nuclear. My view - anathema to readers, I fear - is that Ben Bernanke and Britain's Mervyn King saved us from potential calamity. We were all too close to the tipping point illustrated in Irving Fisher's Debt Deflation Causes of Great Depressions, the moment when the sailing ship catches water and capsizes instead of righting itself by natural rhythm.

Work by Berkeley Professor Barry Eichengreen shows that global trade, industrial output, and stock markets all crashed at a faster rate over the six terrifying months after the Lehman crisis than during the early 1930s. How quickly we forget, and how easily we are seduced by a 76% stock rally into thinking it was a storm in a teacup. Just wait until the day fiscal retribution comes.

The $1.7 trillion created out of nothing will vanish as the bonds are sold on the open market. Not too quickly, let us hope. Easy money must cushion the blow of spending cuts. Even talk of ending quarterly earnings amounts to tightening. While the U.S. economy has begun to create jobs again - plus 114,000 in March, stripping out short-term census workers - there were false dawns in 2002 and 1982. The broader U6 jobless rate nudged up to 16.9%.