Aza Betwata (left) and his brother Mirwan (center) left Holland to join the Kurdish peshmerga fighting against ISIS militants in northern Iraq. Though the brothers come from a family of fighters, Aza had just two days of training — his brother must show him how to strip and clean his rifle. Alice Fordham/NPR hide caption

itoggle caption Alice Fordham/NPR

Syrian Kurdish fighter Delkhwaz Sheikh Ahmad, 22, sits with his wife Siham, 23, and their two sons, Dilyar and Ibrahim, at his brother's house on the Turkey-Syria border on Friday. He was preparing to leave for Kobani, Syria, to rejoin the fighting against the Islamic State. Lefteris Pitarakis/ASSOCIATED PRESS hide caption

itoggle caption Lefteris Pitarakis/ASSOCIATED PRESS

Secretary of State John Kerry (second from left) arrives at Irbil International Airport with U.S. Ambassador to Iraq Robert Stephen Beecroft (fourth from left) on Tuesday. The president of Iraq's ethnic Kurdish region declared Tuesday that "we are facing a new reality and a new Iraq." Brendan Smialowski/AP hide caption

itoggle caption Brendan Smialowski/AP

Rebels of the Kurdistan Workers Party, or PKK, begin to move out of Turkey to bases in northern Iraq, a key stage in the peace process with the Turkish government. Here, PKK fighters are shown near the Turkish border with Iraq on May 7. Firat News Agency/AP hide caption

itoggle caption Firat News Agency/AP