Well... will they or not? In particular, are either of the following scenarios realistic???
https://youtu.be/mGKqMi6ZatQ?si=gNykOFsHyo56eB2_
And...
https://youtu.be/c8jtECzK3gk?si=9ktJ036gw5zgheDS
Plus...
https://youtu.be/6qTNObVSZlg?si=H6LtaZVy_PtjkQxu
So far the consensus seems to be that US nuclear deterrence security guarantees are might be inadequate, barring the push towards the acquisition of nuclear weapons on the part of South Korea. This is because it is expected that North Korea will use nuclear weapons in the opening phases of the conflict...
But either way, if a compelling case can be made in which North Korea won't attempt to invade South Korea, specify what exactly would deter them from doing so?
Update 09/17/2023: Changed "Attack" to "Invade", as that more closely reflects what I mean for this particular question, and to eliminate any ambiguity.