A US M1A2 tank crosses a river during a US-South Korea joint river crossing exercise in the border county of Yeoncheon, northeast of Seoul, on December 10, 2015. The Korean peninsula is the world’s last Cold War frontier as Stalinst North Korea and pro-Western South Korea have been technically at war since the 1950-53 Korean War. REPUBLIC OF KOREA OUT NO ARCHIVES RESTRICTED TO SUBSCRIPTION USE AFP PHOTO / YONHAPYONHAP/AFP/Getty Images
