Asserting their power projection over the DMZ, whether it is legitimate is irrelevant.

It's the same with the development of nuclear weapons. There is a near-zero probability that North Korea will engage in a first strike with nuclear weapons, but a very rational way of self-preservation.

The North Korean regime is reprehensible but their actions are rational, from a self-preservation perspective.

Their demonstrated willingness to defend against even trivial encroachments.