The National Intelligence Service (NIS) will likely want to immediately seek out and eliminate or at least intern North Korean spies and communist sympathizers throughout the country to prevent sabatoge and subversion during wartime.
Inconveniently though many of these people are friends of or friends or friends of President Moon.
This will be really messed up...
What will happen
I will lose all my south Korean anime like
Full metal panic season 4
And all the hentai