I want to know the answer to the following question:
What legal ethos does ISIL operate under?
All the background I'm provided with is that "The US intervened with airstrikes in Iraq over ISIL held territories and assets in August, and in September a coalition of US and Middle Eastern powers initiated a bombing campaign in Syria aimed at degrading and destroying ISIL and Al-Nusra-held territory.". Is that enough to answer the question?
Answer: no