Why Does Obama Call ISIS 'ISIL'?

"Many who closely follow the dueling Islamic terror narratives emanating from the White House are mystified by Mr. Obama's inability (or deliberate unwillingness) to utter the phrase "Islamic terrorists."  Many are curious, too, about why he refuses to call ISIS "ISIS," steadfastly insisting instead that everybody in his administration call the terror group "ISIL."  What's the difference, and why is it important?  The agendas behind each diverge widely.  In fact, the variance between the two is elephantine in scale."

[American Thinker]