Is it possible to grow up believing that others are not as worthy as you are. That there is a difference between you and others based on what you believe? Of course it is.
Most young people attach to one thing or another to their souls as they negotiate with the world. For some it is sport or pursuit of a mate. For others is a religious belief. The developing mind seems prone to go off on terrible tangents. Youth can act with a severity that no other age would likely tolerate or appreciate. The trick is to grow up successfully despite those who would lock us into teenaged angst through our whole lives. These include pederastic predators, certain cults and religious schools as well as dangerous sports and war.
Is ISIS a terrorist organisation, a revolution or simply a creation of the CIA? It probably is all three in its relationship with the external world. But internally it seems to operate like a cult with: hidden language, secrets and revelations, fervent worship of a figurehead, fear, a central philosophy to believe in and a powerful adhesive force that locks people into its grip.
By creating freedom fighter armies the warmongers are able to assist in proxy wars but creating an armed force has a certain danger. They may treat populations as the enemy as would appear to be the case with the ISIL terrorists. By proclaiming a caliphate they seek legitimacy in the modern world by using its technology to enslave and intimidate people.
They arose out of Iraq and Syria and have installed themselves, murdering thousands and enslaving entire populations to their teenaged whims. Their violence is extraordinary and completely out of place in modern civilisation. Are they any worse than Bashir Assad and his civil war and devastation of Syria? They are, because they are fighting a war they want to take to the world. And the world does not want to live like that so resistance is inevitable.
However that speaks of a future, at the present they control much of Iraq and Syria.