After the 2009 North Korean nuclear test , the relationship between Seoul and Pyongyang was again strained . According to Jungmin Kang writing in the '' Bulletin of the Atomic Scientists '' , " Because of the post-1998 ' Sunshine policy ' , many South Korean nongovernmental organizations and the public were n't concerned about North Korea 's threats , believing that Pyongyang would never use nuclear weapons against them . " South Korea 's response to the nuclear test , although dampened by the recent death of its former President Roh Moo-hyun , included signing the Proliferation Security Initiative to prevent the shipment of nuclear materials to North Korea
2009 North Korean nuclear test
2009 North Korean nuclear test
Sunshine Policy