Airstrip One
Completely Effed
We can have a war against entities we don't recognize as states (like we did in the Civil War). While I am against the use of "war" against something as broad as an ideology ("terrorism"), a specific entity like AQ or ISIS is a different matter.
I think the semantic mishap that is the War on Terrorism was simply Bush being too big of a coward to admit he was launching a military campaign against Islamic extremism. He should have specified that his war was with the Taliban government and the al-Queda terror network, because it would have spared us all of these years past (and more still to come) of debating over who and what we are fighting against.