David Kilcullen is a former Australian army colonel, with a PhD in insurgency movements. He has been a counterterrorist adviser to the US and worked closely with Iraq War supremo, General David Petraeus, and US Secretary of State, Condoleezza Rice. Kilcullen is critical of many aspects of the West’s strategy, post 9/11, which, he argues, led to the rise of Islamic State. He warns the global terrorist threat is now the new normal. So how do we defeat ISIS?