A Simple Explanation Of The Rise Of ISIS

ISIS's blitz across Iraq left many stunned this past summer, especially after the jihadist group captured Mosul, the country's second-largest city in June. 

The group's meteoric rise was unexpected and the organization continued to shock the world as the jihadists turned on fellow militants in Syria, executed western captives, and tried to wipe out Iraq's Yazidi religious minority.

To make sense of the organization, the Brookings Institution has released a short video documenting the history of the terrorist group. 

As the video recounts, the predecessor organization of ISIS was founded by Abu Musab al-Zarqawi, who had previously fought alongside Osama bin Laden in Afghanistan. Zarqawi, with support from bin Laden, traveled to Iraq to set up the al Qaeda in Iraq franchise.

After the US invaded Iraq, Zarqawi waged brutal attacks against the American presence, and staged attacks against the Shia majority in hopes of starting a civil war. Zarqawi also popularized the use of brutal tactics such as beheadings to further spread the group's message and instill fear in the population.

Although bin Laden privately disapproved of Zarqawi's penchant for violence and sectarian strife, al Qaeda appointed Zarqawi as the leader of operations for the entire Middle East region because of his effectiveness. 

In 2006, Zarqawi was killed by a US airstrike. In 2010, his successor, Abu Omar al-Baghdadi was also killed by US forces. 

These setbacks, along with the US-led "surge" and the "Awakening" of Sunni tribal militias opposed to Al Qaeda, forced al Qaeda in Iraq underground. The organization renamed itself the Islamic State of Iraq, and in 2012 the Islamic State created a sub-franchise in Syria called the al Nusrah Front which quickly grew to become one of the strongest forces in the country. 

Ayman al-Zawahiri, al Qaeda's leader after bin Laden was killed, announced that Nusrah was al Qaeda's Syrian franchise, independent of the Islamic State.

However, Abu Bakr al-Baghdadi, the leader of the Islamic State, disputed Zawahiri's pronouncement and the two groups began to target each other in the beginning of 2014. 

Today, al-Baghdadi calls himself Caliph Ibrahim. ISIS now rules a contiguous piece of territory about the size of Belgium in Syria and Iraq and has declared itself to be a "Caliphate." A US-led coalition has been bombing the group since mid-August.

You can view the Brookings video below.