Important Research Note: The abbreviations ISIS (Islamic State of Iraq and Syria), ISIL (Islamic State of Iraq and the Levant), and IS (Islamic State) are used interchangeably in the media and in politics. To avoid confusion, we'll use the abbreviation "ISIS." If you see these different names, know that the sources are still talking about the same group.
The Atlantic: How ISIS Spread in the Middle East
BBC News: IS and the Crisis in Iraq and Syria in Maps (great visuals, up to date as of 3/28/2018!)
Bipartisan Policy Center: An Overview of ISIS Threat and US Response
CNN: ISIS Fast Facts (great overview!)
Choices Program @ Brown Univ.: ISIS
Council on Foreign Relations: Explainer - Islamic State
Google Arts & Culture: International Military Intervention against ISIL, 2014
Islamic Networks Group: Overview of ISIS (great overview! click through the presentation also!)
Choices Program @ Brown Univ: The US Invasion of Iraq
Council on Foreign Relations: What to Watch for in Post-ISIS Iraq and Syria (October 2017)
Google Arts & Culture: Iraq War, 2003-2011
Google Arts & Culture: Iraqi Insurgency, 2004-2007
Google Arts & Culture: Operation Desert Shield, 2006
Google Arts & Culture: Iraqi Civil War, 2014
Council on Foreign Relations: Syria (many articles about Syria's current war)
Council on Foreign Relations: Who's Who in Syria's Civil War
Council on Foreign Relations: What to Watch for in Post-ISIS Iraq and Syria (October 2017)
Google Arts & Culture: Syrian Civil War, 2011-Present
Google Arts & Culture: Spillover of the Syrian Civil War, 2011
Google Arts & Culture: Operation Inherent Resolve, 2014