If North Korea wants to be on our radar, we should give them a response they're unprepared for.
It appears that North Korea has launched cyber attacks on the US. We should meet such acts of war with a strong military response. Lobbing a couple of missiles into North Korea's army headquarters would send a message that we're prepared to deal with their bullshit, and throw their military communications into chaos should they retaliate with a march across the South Korean border. We can't let North Korea feel for an instant that they can predict our actions OR inactions, and should let them know that further attacks on the US will not be tolerated. They have a few nukes but we have thousands. Clearly nuclear deterrence and statesmanship have failed us.