Albeit long, this well sourced summation of financial ties to IS/ISIL/ISIS is worth reading/bookmark:
The Long Arm of Qatar
It ties Turkey and the U.S. To this nightmare
In addition to the above, further confirmation of this administrations complicity, consider:
Obama's preference for the identity of ISIL vs. IS or ISIS via Financial Times
&
Flashback: Here's What’s Happened Since President Obama Freed the Leader of ISIS 5 Years Ago
In June, we learned that the head of ISIS, Abu Bakr al Baghdadi, had been in US custody but was released in 2009 when President Obama closed down Camp Bucca in preparation for the US withdrawal of troops (yes, the withdrawal he repeatedly denies having anything to do with) from Iraq.