ISIS originally stood for Islamic State in Iraq and Syria and then the term became ISIL or Islamic State in the Levant.
The Levant has historically and in modern terms not included the area that is Afghanistan so seems to me the US Military is doing a very poor job of keeping this country free from the spread of such opposition. Or just maybe the opposition is a whole other manifestation and the propaganda arm of the US Empire State is just calling it ISIS and hoping we won't begin to see what might be taking place.
There is a reason Afghanistan has always been called the "Graveyard of Empires" and I see no reason whatsoever to view that this well earned label no longer applies.