They did not manage to form a state! Where do you get your information?
They have formed a state dumbass, just because they aren't recognised by the other countries doesn't mean they haven't, much like how the Kurds are holding their own in Iraq and have their own territory I recognise that as a state even if Americans won't, ISIS even have their own financial centre and healthcare supposedly, of course, all of the money is plundered from the U.S lol but they're using the oil they captured and are selling it to other countries to fund themselves.
Just because someone calls themselves "the State of _____", doesn't make them a state! I asked you: where do you get your information from? Because it sounds like you believe exactly what ISIS says. And I'm the dumbass? LOL
It's not even about them calling themselves a "State of...", the western media/politics officially named them a 'State'.
ISIS = Islamic State in Iraq and Syria