Why is the capitalist world backing every conceivable thug and bombing the Islamic State like crazy. The answer is simple. A huge oil crash is looming:
Only nine of 33 shale oil exploration and production companies reviewed in the report cited above had positive free cash flow for the first half of 2018. This is even though prices had risen all the way from a low of around $30 in 2016 to the mid-$70 range by the middle of this year.
Forecasts for world oil supply depend on a sharp increase of production from the Kirkuk, Iraq fields. But the IS has made drilling there unsafe. So while waiting for their defeat, the US has ramped up shale oil. But US oil is being pumped with borrowed money. [see linked article]
MbS will stay, they need him. Fascism will be needed in the US. As for the IS, they cannot defeat it with bombs, because each bomb brings ten recruits.