Syrian revolutionaries
A poster advertising the 'day of rage' rally in April 2011, where tens of thousands took part in anti-government rallies across the country. At least 50 protesters were shot dead by Syrian security forces that day.
That is according to documents uncovered during a raid on the home of Abu Sayyaf, the ISIS "oil minister" who was killed by US Special Forces at his compound in Syria's Deir Ezzour province in May 2015.
Abu Sayyaf's division - which had successfully negotiated agreements with the Assad regime to allow ISIS trucks and pipelines to move from regime-controlled fields through Islamic State-controlled territory - helped the jihadists bring in roughly $40 million per month in oil sales alone, according to documents seen by The Journal.
Though Sayyaf was killed, his oil infrastructure remains largely intact. ISIS still controls the majority of Syria's oil fields, and the group continues to bring in roughly $1 million per day from oil sales, according to the Financial Times.
The Assad regime's oil ties to the Islamic State have been well documented. At least two Syrian government officials, including a Russian-Syrian businessman named George Haswani, were sanctioned by the US last year for serving as middlemen between Assad and ISIS for oil deals.
The Daily Beast reported in December, meanwhile, that ISIS delivers both oil and natural gas to the regime. The report said the resources are transported via "midstream" service providers who move the resources from ISIS territory to government territory for profit.
"In exchange for gas, the regime provides utilities like electricity, which ISIS taxes accordingly," wrote Matthew Reed, the vice president of Foreign Reports, Inc., a Washington, DC-
"At natural gas fields like those around Palmyra, which produce lighter liquid hydrocarbons in addition to gas, ISIS takes whatever it can turn into fuel," he continued. "The gas goes west to Assad."
Khalil Ashawi/Reuters Men work at a makeshift oil refinery site in Marchmarin town, southern countryside of Idlib, Syria in this December 16, 2015, file photo.
One document, identified as Memo No. 156 and dated February 11, 2015, said agreements allowing trucks and pipeline transit from regime-controlled oil fields through ISIS-controlled territory were already in place.
The documents also confirmed previous estimates as to how lucrative the deals were. A senior US treasury official estimated in December that ISIS has made more than $500 million trading oil with the Assad regime, which amounts to roughly $40 million per month.
ISIS' oil ties to governments did not begin and end with Assad, however. Last July, The Guardian's Martin Chulov reported that separate documents uncovered in the Sayyaf raid linked Turkish officials to ISIS as well.
Flash drives seized during the raid reportedly revealed links "so clear" and "undeniable" between Turkey and ISIS "that they could end up having profound policy implications for the relationship between us and Ankara," a senior Western official familiar with the intelligence told The Guardian at the time.
Ankara, long accused by experts, Kurds, and even Vice President Joe Biden of enabling ISIS by turning a blind eye to the vast smuggling networks of weapons and fighters during the ongoing Syrian war, has vehemently denied participating in any kind of illicit oil trade with the militant group.