The wise man does not poke a sleeping tiger in the ear, even with a stick.
As a psychiatrist, I would advise the neighbours of a known person who suffers from paranoia not to, for instance, knock on the shared wall, and not to play loud music, as these actions might be misinterpreted by the paranoid mind.
Some will say that South Korea has a perfect right to play military games. I would question the "perfect". In a perfect world, nobody would conduct military exercises, because there would be no military.
Given, though that the Koreans are are already noted for their military prowess, it is questionable why South Korea has to play games near the border. It is analogous to knocking on the wall of a person with paranoid schizophrenia.
More on Korea here.