U.S. soldiers and service members with the NATO-led International Security Assistance Force (ISAF) attend a religious ceremony on Christmas Eve at Bagram military base in Kabul, Afghanistan, Tuesday Dec. 24, 2013. (AP Photo/Rahmat Gul)

Photo by: Rahmat Gul

U.S. soldiers and service members with the NATO-led International Security Assistance Force (ISAF) attend a religious ceremony on Christmas Eve at Bagram military base in Kabul, Afghanistan, Tuesday Dec. 24, 2013. (AP Photo/Rahmat Gul)