What happens when North Korea chucks a nuke at the South Koreans tomorrow?

seems like this morons life is ending and he wants to take the world with him,i have a slight feeling that south k and the united states have a plan set up that will TRY and knock down any nukes this fool tries to get off,then we will just end this country,the north seems to want to commit Harri cari and lets just do it for them,and china do sent want them to use nukes anymore than anyone else,so they too will shoot a missile out of the sky,one nike will ruin China's air,sea and economy and they don't want that