In the course of a few years, the Islamic State of Iraq and Syria--more commonly known as ISIS--has become classified as the most dangerous terrorist organization in the world. It is the subject of intense Western scrutiny, demonized by all, and shrouded in numerous myths and narratives.

Against these established narratives, Mohammad-Mahmoud Ould Mohamedou now presents his new theory of ISIS. Tracing the genealogy of ISIS and documenting its evolution in Iraq and Syria, he argues that ISIS has actually transcended Osama Bin Laden's original scheme of Al Qaeda, mutating into a...