Covid-19 crept up on a world economy already in the grip of an oil price war between Saudi Arabia and Russia. Moscow and Riyadh boosted output in the first weeks of 2020 to reckless levels while prices fell dizzyingly. Then lockdown across the West, not least in the USA, kicked in and collapsed energy prices.

President Trump initially celebrated cheap gas, but he has since come to see the negative impact not just on US shale production but on America’s key allies. High energy prices can cause a recession in the West but giveaway prices can cause global upheaval.

1986 was when oil prices were last so low. It was also the year of Chernobyl. That disaster symbolised Soviet incompetence. But it was also the year Ronald Reagan got the Saudis to boost oil production, slashing the Soviet Union’s income from its energy exports. Moscow could no longer afford its intervention in Afghanistan and its subsidy to the “socialist commonwealth”, from Cuba to North Korea.

Low oil prices were the backdrop to the collapse of Communism and the emergence of the United States as the world’s only superpower. Another geopolitical upheaval is on the cards, but this time the West and particularly its Arab allies could be the losers.