North Korea is not going to launch a nuclear missile against the U.S. unless the U.S. attacked first.    Why does the U.S. government think this?  Kim Jung Un is not crazy or stupid.  We need to accept that NK has nuclear weapons and back off with the threats and sanctions (which are totally ineffective because 90% of NK trade is with China and the rest with countries which are anti-U.S.)

Let South Korea deal with North Korea.  It's been almost 70 years since the Korean War ended and South Korea should have been able to establish better relations with them in all that time.  Frankly, South Korea has played the U.S., created a huge bustling economy, and basically left the U.S. to worry about the defense of SK and SK/NK relations.