The extension of the 24-nation oil production cut agreement initially reached last December should ensure prices remain at about $60 a barrel in 2018.

The deal engages countries producing about 50 million barrels a day (b/d), including Russia, the world’s largest oil producer, and Saudi Arabia, the leading exporter. That is more than half the global total.

The Opec/non-Opec declaration of cooperation could be one of the most important deals in oil industry history. Opec is calling for more producers to join the pact and is inviting consuming nations to join too. The primary goal is to prevent the oil price collapsing again as it did between the summer of 2014 and January 2016.

But it is also a way of preventing the emergence of unsustainable peaks. The long-term aim is stability, which produces a price high enough to maintain the solvency of oil exporters and incentives for investment, but low enough to keep hydrocarbons demand growing.

The Opec/non-Opec deal presented in that way serves a purpose that extends beyond the self-interest of the oil sector to all energy consumers.

The problem is it does not include the US, where oil output in October was more than 9.5 million b/d. That could reach 10 million b/d this time next year. Independent US oil companies, particularly those focusing on shale, are responding to the price recovery and will continue to do so if oil stays at or above $60 a barrel.

The production cut has lifted oil prices by more than 10 per cent since the start of January 2017, but ensures they will be under persistent downward pressure in 2018.

Opec and its non-Opec partners need a helping hand from the US oil industry. But there is no sign this will be forthcoming, as UAE Oil Minister Suhail al-Mazrouei told me in Abu

Dhabi in November.

“There are so many producers [in the US], it is almost impossible to get them together and the US doesn’t have a national oil company,” Al-Mazrouei said. Suggestions that American oil companies should join the pact would also be politically contentious and attract anti-trust action as well.

But would extending the declaration of cooperation to the US government make sense? “That would be great if we could achieve it,” Al-Mazrouei said.

There is no prospect that Washington will support the Opec/non-Opec deal. But the US needs stability in the energy market if it is to mobilise the investment its economy requires.

The pact will probably work in 2018 and may be extended again. But for its impact to be lasting, it needs friends in the US.