Peter Kassig, the 26-year-old American aid worker beheaded by ISIS, was a former Army Ranger who left the service to commit his life to humanitarian missions in the Middle East.
It was while on one of these missions in Syria in October 2013 that Kassig was kidnapped by terrorists who would later execute him.
According to the Huffington Post, Kassig served as an U.S. Army Ranger, deploying to Iraq in 2007 before receiving a honorable discharge to due medical reasons.
In March 2012, Kassig wrote an email from Beirut, detailing his plans to stay in the Middle East:
"Here, in this land, I have found my calling...
"I do not know much, everyday that I am here I have more questions and less answers, but what I do know is that I have a chance to do something here, to take a stand. To make a difference."
