By Simon Kent.
When Coalition aircraft began targeting ISIS oil operations last year, they did so under strict rules of engagement that were designed to minimize civilian casualties: many of those transporting the oil were deemed civilians trying to earn a living under ISIS rule.
Tactics in the early days of the Tidal Wave II bombing operation involved targeting mostly modular refineries and oil wells, hitting the 200 wells in Syria and hammering ISIS oil production from 70,000 bpd to around 40,000 bpd.
In Iraq, the fields under ISIS control such as Qayyara near Mosul, produced only 8000 bpd of very heavy crude, and this is now thought to be an almost crippled operation, since fuel costs in Mosul are now extremely high.
Subsequently, oil fell from being a main source of cash for the group to being only a fragment of their income, a fact revealed by documents captured by a US Special Forces raid into Syria. That raid killed the chief of ISIS oil operations, known as Abu Sayyaf.
Things only got worse for the group as the US decided to finally target ISIS oil tanker trucks, dropping warning leaflets to the truckers instructing them to run from their vehicles. The raids hit hundreds of tankers near Al Qaim in Iraq in late November.
Russia soon joined these strikes, which probably destroyed the majority of available fuel trucks in ISIS territory.
ISIS has since been more reliant on small home made refineries that according to one US official, resemble pre-20th century production. The group struggles to get more than $20 per barrel for this oil, which is mostly sold within Syria and is probably hitting less than 30,000 bpd production.