Americans are purging their excesses one by one. Spending by the US Federal government has seen the steepest drop as share of national income since demobilisation after the Second World War.

Claims that President Barack Obama is bankrupting America with a lurch towards hard-Left statism are for tabloid consumption only. Outlays have fallen from 24.4pc to 20.6pc of GDP in five years. Spending is roughly in line with its 40-year average. This fiscal squeeze has been achieved without driving the economy into recession or a Lost Decade, a remarkable feat.

The US Congressional Budget Office expects the budget deficit to drop to 2.8pc of GDP this year, and 2.6pc next year. This is about the same as the eurozone but with a huge difference. The US economy is expanding fast enough to outgrow its debts.

The US energy revolution is of course half the story. It has stoked booms across the Dakotas, Wyoming, Nebraska, Washington, Oregon, Utah and Texas.

Francisco Blanch, from Bank of America, estimates that shale gas and oil have given the US economy an extra tailwind worth 1.9pc of GDP - what he calls the "energy carry" - with effects rippling through the chemical and plastics industries. New investments in ammonia plants are rising at an exponential rate, thanks to natural gas prices that are $4.40 (per BTU) in the US and $15 on Asia's spot market.

The US transferred more than $3 trillion to oil exporters from 2001 to 2008. That chapter is closed. The US is back to where it was in 2000 with an energy deficit well below 2pc of GDP and improving every month, while the eurozone is at -4.4pc and getting worse, and Japan is at -6.3pc.

The US has added 2.5m barrels a day of crude output over the last three years, almost as much as the next three countries combined. America covered a quarter of its oil needs in 2007. It covers well over half today. It has overtaken Russia to become the world's biggest exporter of refined petroleum products, and will soon be an exporter of liquefied natural gas as well.

David Fuller's view

I preferred the newspaper title for this article: Writing off America was foolish… now it’s on the brink of a golden age.

I do maintain that the US economy is enjoying a process of revitalisation.  However, success is impermanent, often to the point of being ephemeral, especially when governance fails. 

I credit one man for enabling the US economy to outperform most others, as we are currently seeing.  Fittingly, he was not a politician but a gritty, hardworking Texas oil man named George Mitchell, the father of fracking.  I have mentioned him previously including in this item on 7^th November 2011, and I am very pleased to see that fracking has enabled the US economy to become virtually energy dependent far faster than I predicted.

Fracking has given the US economy a huge competitive advantage in energy costs.  This has resuscitated the US ‘can do’ spirit, leading to a resurgence in technological developments, expanding a lead in many areas that had been previously contracting.

The US economy now has the potential to outgrow its debts, as Ambrose Evans-Pritchard points out above.  I remain a long-term optimist and think it will do so with the help of competitive energy prices and technological innovation.  However, there are always obstacles to be overcome, including complacency, reoccurring lapses in sound governance, and rogue events such as Vladimir Putin’s old Soviet-style aggression, which the US and Europe will hopefully face with increasingly firm economic sanctions, despite the inevitable temporary cost.  In addition to Putin, we can be sure China is watching closely.