In the aftermath of the March 2011 Fukushima nuclear disaster , Korea added a new issues of radiological security and the nuclear security-safety interface to the agenda from the natural disasters since World War II ( 1939-45 ) and Korean War ( 1950-53 ) . The Washington summit had focused on nuclear terrorism with explosive nuclear devices , perceiving that as the biggest threat to international security after 9/11 attacks in New York City in 2001 , 3/11 train bombings in Madrid in 2004 , and 7/7 bombings in London in 2005 . The ' '' 2012 Seoul Nuclear Security ' '' summit also discussed protection against dirty bombs and the sabotage of nuclear facilities
9/11 attacks
September 11 attacks
2012 Nuclear Security Summit