3. Mosul, Iraq

Dubbed “the Mother of All Battles” of the Iraqi Civil War, this vicious bloodletting broke out in October 2016 and still rages on. Iraqi Security Forces and their allies tried to retake the city from ISIS. The ISF captured eastern Mosul in late January 2017, but the end is nowhere in sight. Casualty claims are heavy from both sides ranging from 1.000 to 6.500 for ISF troopers and 2.000 to 4.000 for ISIS combatants.