Meglet
Forgive me asking a blindingly stupid question blush. We know how awful life is for people in NK, lack of food etc. Are we sure they have nuclear weapons or it's just them bullshitting?
We can tell when they set off a nuclear weapon because they do it underground and seismographs pick up the shockwave. A nuke detonation has a very specific shockwave.
Can't the rest of the world invade and free everyone?
What? Why? Assuming we did 'invade and free everyone', who would we install as replacement? There's no government-in-waiting, it's a Stalinist state where anyone who says "That Kim bloke's a bit of a wrong-un" gets shipped off to the Gulag, from which they do not return.
Surely we have more knowledge about them than they do about us so could get in easily.
The 38th Parallel - the border between NK and SK - is the most heavily defended in the world. The casualties from a land-borne invasion would be catastrophic.
Or are SK just too much at risk if anyone starts a war first?
How many casualties do you think the US or British public are prepared to sustain to enforce regime change? The last time they went at it in Korea 36,000 Americans died. This time casualties would be far worse because NK, being a Barking Mad Barry country, would use its nukes. My guess would be at least 10 million dead on both sides.