Kim Park-Chu was a North Korean Colonel. He was a former commander of Chemical Bunker. He did the opposite when NKA decided to end the fighting and leave Seoul - he and a small group of NKA defectors carried warheads armed with biological weapons and occupied Grand Central Station in Manhattan. Third Echelon thwarted a possible biological attack by Kim's man Chu by sending in Agent One and Agent Two.
Third Echelon later found out that the detonator Kim used came from a nuclear plant in Yongbyon, North Korea, and that Kim had Jin Soo's help to prepare the detonator. Kim eventually showed up at UN Headquarter in Manhattan and tried to plant another bomb in New York. Agent One and Agent Two managed to stop Kim and his men to disarm the bomb. Agents can't grab him from behind.