South Korean soldiers walk near their armored vehicles during an exercise near the border village of Panmunjom, which has separated the two Koreas since the Korean War, in Paju, north of Seoul, South Korea, Tuesday, March 12, 2013. North Korea's young leader urged front-line troops to be on "maximum alert" for a potential war as a state-run newspaper said Pyongyang had carried out a threat to cancel the 1953 armistice that ended the Korean War. (AP Photo/Lee Jin-man)