I found this
ISIS or ISIL? The debate over what to call Iraq?s terror group - The Washington Post
ISIS=Islamic State of Iraq and Syria
ISIL=Islamic state of Iraq and Levant
The claim is that this is due to ISIS being active in a greater region than Iraq and Syria.
My personal opinion, it is to separate ISIS from Syria due to the fact the we funded the shit out of them and helped to make them what they are today by sticking our nose in some shit we shouldn't have.
We armed them in Syria, now we will have to fight then in Iraq. The WH is changing the name in hopes of creating a disconnect. JMHO.
ISIS, ISIL, IS. Same shit different name lol.
I believe the way we name things effects the perception.