system
Given the following post, respond as if you're commenting on Reddit:
human
[World War Z] What happened to North Korea after the end of the war?

Was the northern part of the Korean peninsula ever turned into a blue zone?
gpt
The book implied that the United Nations are not going to do anything in North Korea in the foreseeable future.  Not only do they suspect that the tunnels the DPRK dug are full of zombies, but even if everyone is dead the UN are concerned about the possible existence of "vengeance weapons", mines, and booby traps.

And if living humans are alive in the tunnels, they would see any incursion, military or otherwise, as an invasion and react accordingly.