What makes the "Islamic State" so dangerous. After its brutal conquest in 2014, the "Islamic State" now rules over more than five million people and an area the size of Great Britain. SPIEGEL correspondent Christoph Reuter traces the meticulously planned rise of the jihadists and delves into the roots of terror - in the collapsing Iraq, in the Syrian civil war, and in the various conflicts of the region, which the strategists of terror skillfully exploit for their purposes. IS, the "Islamic State," is much more than the most dangerous terrorist group in the world. It is a power that demonstrates an unprecedented level of perfection - in its actions, its strategic planning, its completely unscrupulous shifting of alliances, and its precisely deployed propaganda. The jihadists do indeed demonstrate their faith.