Opec has tied itself in a knot. The oil producers’ cartel, divided over the need for output increases to curb soaring prices, decided on Wednesday that the best course of action was not to act. Keeping production levels unchanged will support international oil prices in the short term. The bigger worry, though, is that Opec’s internal struggle will stoke price instability.

Saudi Arabia, the cartel’s de facto leader, says demand and supply are balanced and that there is no need for an increase. The truth is that Opec’s hawkish members are in the ascendancy. The influence of Algeria and Venezuela, which want to see prices at $100 a barrel or more, has grown steadily.