Excuse me but since the Korean War, what "aggression" has NK undertaken?

[sl8]

15. Attempted assassination of South Korean President

Blue House raid:
https://en.m.wikipedia.org/wiki/Blue_House_raid

The Blue House raid (also known in South Korea as the January 21 Incident) was an unsuccessful attempt by North Korean commandos to assassinate the South Korean president, Park Chung-hee in his residence at the Blue House, on January 21, 1968.

...

During the course of this assassination attempt, South Korean casualties totaled 26 killed and 66 wounded, including about 24 civilians. Four Americans also were killed in attempts to block the escaping infiltrators from crossing the DMZ.[5] Of the 31 members of Unit 124, 29 were killed; one, Kim Shin-Jo, was captured,[6] and the other one, Park Jae-kyung escaped to North Korea.[7] The bodies of the members of Unit 124 killed in the raid were subsequently buried in the Cemetery for North Korean and Chinese Soldiers.[8]

...

More at link.