Everyone knows (or should know by now) that the US govt. created ISIS as a proxy mercenary army in order to carry out 'regime change' in the Middle East, most recently in Syria. Everyone should also be aware of the fact that the US government has been spending large amounts of US taxpayer dollars on training and arming this jihadi army. It's only logical, therefore, that as the relationship deepens, the US would take the next step of personally transporting the jihadis to specific destinations. That is, in fact, what happened recently when, as reported by the BBC:
"US-led coalition aircraft have for the first time carried out an airlift of allied fighters battling the jihadist group Islamic State (IS) in Syria.

The Pentagon said members of the Syrian Democratic Forces (SDF) alliance were dropped behind IS lines close to the Tabqa dam, west of the city of Raqqa.

Fierce fighting was continuing around the dam, thought to be a base for hundreds of foreign fighters, it added."
No one should be fooled by the labeling of these jihadis as "democratic" and "anti-ISIS". Given that they are a private army of the US government, they clearly share the same goals as the US government, which is to continue the destruction of Syria in the hope of deposing Assad. If that can't be achieved, 'plan B' is to use these mercenaries to create a 'Kurdistan' in Northern Syria and Iraq (and possibly Southern Turkey) in order to:

a) cut off Iranian influence in the area and access to the Mediterranean for its oil and gas

b) prevent Russia from supplanting the USA as the dominant foreign power in the region

c) ensure that the US government's headchopper and dictator allies in the region - Saudi Arabia, Qatar and the UAE - remain the Middle East's main energy suppliers to Europe, China and the rest of the world.