The homeless vet Ray talks to has a tattoo on his arm that has a unit insignia and says "Big Red One", Ray tells him they might have worked together in Ghazni back in 2012 (Operation Enduring Freedom XIII). Big Red One is the official nickname for the United States Army's 1st Infantry Division, as the nickname implies their unit insignia is a red "1". The 1st was formed in 1917 during World War I and is the oldest continuously serving division in the Regular Army. Based out of Fort Riley, Kansas the 1st has participated in every war and major military operation of the past century, they saw heavy fighting post 9-11 during the Iraq War, especially in the First and Second Battle of Fallujah; they also saw a lot of action in Afghanistan during Operation Enduring Freedom and Freedom's Sentinel. The 1st also participated in the joint international military intervention against the Islamic State in Iraq and Syria in 2018 known as Operation Inherent Resolve.