The six nations of the Gulf Cooperation Council (GCC) -- Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates -- could soon start reeling from falling oil prices, which have dropped by half from their 2014 highs to around $60 a barrel.
Pumping about 17.5 million barrels per day, GCC countries are forecast to lose at least half their oil revenues, or around $350 billion a year, at current price levels.
Oil revenues make up around 90 percent of income for most GCC states and with prices now below budget forecasts, their governments are looking at certain deficits next year.
Spending cuts are sure to follow -- and possibly even the region's first taxes -- raising fears of public discontent and eventually an economic slowdown.
The oil price drop has also sent Gulf stock prices plummeting, wiping out billions of dollars of market value across the region and hurting major private firms like developer Emaar Properties and builder Arabtec Holding.
The heart of the problem, leading Kuwaiti economist Jassem al-Saadun said, is that Gulf states failed to seize on surging energy revenues to build up their economies outside the oil sector.
"Gulf states have missed an important opportunity to reform and build a real diversified economy," Saadun said.
"Public spending has soared to new record highs and it was not for vital infrastructure projects to diversify the economy," Saadun said.
"It was mostly for wages, salaries and subsidies... and handouts for buying political loyalty especially after the Arab Spring."
Reserves only 'temporary cushion'
Economists are warning that even with the huge reserves many have built up, a prolonged drop in oil prices will hit Gulf states hard.
"The prevailing growth model for most oil-exporting countries has left them vulnerable to a sustained decline in oil prices," the International Monetary Fund said in a research bulletin last week headlined: "It is high time to diversify".
Ratings agency Standard & Poor's is warning that an extended decline in oil prices will likely slow the Gulf economies, reducing spending on their massive infrastructure projects and hitting the private sector.
S&P has lowered its outlooks for Saudi Arabia, Oman and Bahrain, though it has maintained their ratings because of their impressive reserves.
The IMF has said that -- barring Oman and Bahrain, which are already in deficit -- GCC states will not be greatly affected in the short-term as they can tap into reserves estimated at $2.5 trillion.
