The Islamic State has entered into a slow decline that will continue throughout 2017. After its inception, the group energized the jihadist movement and drew thousands of enthusiastic foreign fighters by announcing the creation of a caliphate and assuring its followers that the end of the world was near. This enabled the Islamic State to rapidly amass manpower and capabilities — at least at first. But both time and geography have worked against the organization since its initial proclamation of a caliphate and an impending apocalypse. Despite the Islamic State's frequent and pointed criticism of al Qaeda leader Ayman al-Zawahiri, the group has roughly followed the plan al-Zawahiri laid out in a 2005 letter to Abu Musab al-Zarqawi , who was then the head of the Islamic State's predecessor, al Qaeda in Iraq.