Iraq’s southern provinces are attempting, against long odds, to force Baghdad to pay them what they are “owed” under the “petrodollar” appropriations which have been incorporated into budgets and other laws in recent years. A new court ruling has just made the task more daunting.

On 23 November, Basra Provincial Chairman Sabah al-Bazuni declared that the province had sued the Finance Ministry over the petrodollar payments, claiming that Baghdad owed it ID16trn...