This may be the answer. I don’t know who wrote this, nor do I care. It does offer a credible suggestion as to why obama almost immediately began referring to isis as isil. See comments.
ISIS or ISIL? Why this Obamaspeak? What is the difference? I noticed Obama used the term ISIL in his speech, so I take it, it does have considerable meaning. I’m not sure why he has chosen to refer to the terrorists in Iraq in that way, but I am sure it will become apparent at some point.
What difference does. it. make, you may ask? It most certainly helps his position or image in some way.