![Ali Khamenei (right) in a trench during the Iran-Iraq war, 1980s.](/sites/default/files/styles/large/public/Ali_Khamenei.jpg?itok=od7Hc2Fy)
Ali Khamenei during the Iran-Iraq war
![A joint US–Iraqi Army training exercise.](/sites/default/files/styles/large/public/US-Iraqi%20training.jpg?itok=h7gcDBK8)
November 2009 training exercise
![Hasan ibn Ali served his father, Ali, during the Battle of Siffin.](/sites/default/files/styles/large/public/4%20Balami_-_Tarikhnama_-_Battle_of_Siffin.jpg?itok=Et-A-UAi)
Battle of Siffin, 657 CE
![Pilgrims gather for the ashura commemoration in Karbala, Iraq.](/sites/default/files/styles/large/public/5%20aschura.jpg?itok=GmXJYex3)
Ashura commemoration
![The Battle of Karbala, 680 CE.](/sites/default/files/styles/large/public/6%20battle%20of%20karbala.jpg?itok=R4nGZM-X)
Battle of Karbala, 680 CE
![Members of the U.S. Army pose under the 'Hands of Victory' sculpture.](/sites/default/files/styles/large/public/14%20US%20Iraq%20invasion.jpeg?itok=fXe_FBfK)
Members of the U.S. Army in Iraq, 2003
![Millions of Shi'i Muslims gather around the Husayn Mosque.](/sites/default/files/styles/large/public/1024px-Kerbela_Hussein_Moschee.jpg?itok=x3q73a4f)
Husayn Mosque in Karbala, Iraq