The dramatic rise of the Islamist State (IS) in 2014 spelled a game changer in the West's fight against Islamic jihad. From its origins in Afghanistan and Iraq under the leadership of Abu Musab al Zarqawi, and its announcement of the new Islamic Caliphate under the self-proclaimed caliph Abu Bakr al Baghdadi, to its rapid proliferation throughout the world, IS has become the standard bearer for global jihad and the purest expression of Islam on earth...