** FILE ** South Korean President Lee Myung-bak attends a briefing at the Joint Chiefs of Staff in Seoul in November 2010  as the military was put on top alert after North Korea's artillery attack on a South Korean island of Yeonpyeong. (Associated Press)

** FILE ** South Korean President Lee Myung-bak attends a briefing at the Joint Chiefs of Staff in Seoul in November 2010 as the military was put on top alert after North Korea's artillery attack on a South Korean island of Yeonpyeong. (Associated Press)