North Korea – What happens if…

Probably doesn’t belong here or else where, but I have posted a fair bit on these forums and you lot normally have considered responces.

So I would like to here your what happens next in this scenario.

The meeting of the Workers’ Party of Korea takes place on 28 September.

It is the first such gathering in 30 years and is expected to pave the way for the transfer of power from Kim Jong-il to his son, Kim Jong-un.

As Kim Jong-il shuffles out in front of all his lakies – multiple tomahawks, launched from 2 Los Angeles class attack subs lurking in the East China sea, hit home and wipe out the entire Workers Party.

What is the likely follow on from this, and what would America need in place to execute this?