In this Dec. 17, 2011 photo, soldiers from the 3rd Brigade, 1st Cavalry Division, attend a casing of the colors ceremony by handwritten names of soldiers at Camp Adder, now known as Imam Ali Base, near Nasiriyah, Iraq. Around 500 troops from the 3rd Brigade, 1st Cavalry Division ended their presence on Camp Adder, the last remaining American base, and departed in the final American military convoy out of Iraq, arriving into Kuwait in the early morning hours of Dec. 18. (AP Photo/Mario Tama, Pool)

A look at US personnel in Iraq

U.S. personnel in Iraq, where the United States launched airstrikes to protect American personnel and assets threatened by Islamic extremist…