A man looks at the display showing possible damage if a 1 megaton class nuclear weapon is detonated in Seoul, at the Korea War Memorial Museum in Seoul, South Korea, Tuesday, April 2, 2013. North ... more 
A man looks at the display showing possible damage if a 1 megaton class nuclear weapon is detonated in Seoul, at the Korea War Memorial Museum in Seoul, South Korea, Tuesday, April 2, 2013. North Korea vowed Tuesday to restart all mothballed facilities at its main Yongbyon nuclear complex, adding to tensions already raised by near daily warlike threats against the United States and South Korea.(AP Photo/Ahn Young-joon) less 
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Associated Press | Photo By Ahn Young-joon
Tue, Apr 2, 2013 7:36 AM EDT