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FILE -- In this Sept. 22, 2016 file photo, fighters of the Libyan forces affiliated to the Tripoli government rest and reload weapons during an offensive against Islamic State militants, in Sirte, Libya. The Islamic State group lost the battle for the city of Sirte, Wednesday, Dec. 6, 2016, losing its only foothold in Libya, essentially ending the militants’ ambition to expand its self-styled “caliphate” beyond Syria and Iraq. But that victory only opens the door for Libya’s multiple armed factions to potentially turn on each other in a new showdown. It is likely to be over control of oil, the North African nation’s only real source of revenue. (AP Photo/Manu Brabo, File)

Iraq War

President Obama announced on Oct. 21 that the United States is pulling all its troop from Iraq by the end of the year. (ABC News)