IRAQ/SYRIA

The reported arrests of Kurdish officials accused of oil dealings with the Islamic State of Iraq and Greater Syria (ISIS) near to the Kurdish-controlled northern Iraqi oil city of Kirkuk indicates that the business of smuggling oil by the extremist group continues. But volumes are falling as the US and its allies have made repeated attacks against oil installations and refineries held by ISIS.

Just how much is being produced and sold to fund the military campaigns in Syria and...