Kellie Pickler, country music artist, sings for airmen at the USO Holiday Troop Visit on Royal Air Force Mildenhall, England, Dec. 10, 2014. This was Pickler’s eighth USO tour. Kellie Pickler, country music artist, sings for airmen at the USO Holiday Troop Visit on Royal Air Force Mildenhall, England, Dec. 10, 2014. This was Pickler’s eighth USO tour. SHARE: Download: Full Size (3.15 MB) Tags: Photo Essays Credit: VIRIN: 213402-H-BVP22-830.jpg Photo Gallery