In order to raise funds, in July 2015, Saudi Arabia sold bonds for the first time in eight years, a move that was followed by the sale of the equivalent of $5.3 billion in bonds on August 10.

Yet as the population of 30m grows, and especially if the oil price remains low, it will have to reform as well as borrow. Brent crude is trading at about $48.52 (£31) per barrel, compared with $107 (£69, €98) in June 2014, largely due to massive overproduction by Riyadh, which is pumping out 10.6 million barrels per day.

At the same time, oil markets are discovering what it is like to operate under the regime of a new swing producer: the United States.

Real GDP growth is projected to slow to 2.8 per cent this year, and then further to 2.4 per cent in 2016 as government spending begins to adjust to the lower oil price environment. “If prices stay low, I expect more anti-western rhetoric and a ramping up of the war, to distract public attention and heap blame on the West”, he said.

In general, the latest forecasts show that oil prices may remain at a low level for several years, according to the expert.

In February, Standard and Poor’s downgraded Saudi Arabia from stable to negative, warning the economy is “undiversified and vulnerable to a steep and sustained decline in oil prices”. From the shutdown of additional rigs to the curtailment of new investment in exploiting shale resources, the US will likely experience a fall in its absolute energy production, as well as in its share of world output.

In Venezuela which has a world’s biggest oil reserves the opposite applies. Within a few years, it will have overtaken Saudi oil production and will be the swing producer again. “We get nothing for it”.

Their other, bigger mistake was to believe that victory was possible at all. “You go and knock the hell out of the oil”. The pores in the oil-bearing rock clog up, and that permanently reduces the “bottom-hole” pressure that forces the oil to the surface. Uncap it, and the flow resumes as before.

“We’re still in the market, but we’re increasingly getting risk-averse to preserve the capital that we have”, Shabbir said. The annual budget should be set within a medium-term fiscal framework that clearly establishes the authorities’ policy intentions, fully integrates the expenditure priorities from the national development plan, and delinks expenditures from short-term volatility in oil revenues while ensuring that spending adjusts to longer-term price trends. They’re holding steady with their prices until they’ve secured relationships with the countries that need energy.

The Saudis will stay rich, but they will have to cut their spending and they will suffer a permanent loss of influence.

Today, indicators of this global slowdown are to be found everywhere – from underwhelming retail and trade data to unanticipated policy responses, including China’s surprise currency devaluation (which coincides with its leaders’ commitment to a long-term shift toward a more market-based exchange-rate regime).