A normal U.S. President would not fly to the other side of the world for a major agreement unless we knew it was a done deal.
Exactly why a "done deal" has never been accomplished by the last 4 Presidents. After all those fails, don't you think it would be wise to try a new approach? Or should Presidents continue to follow a precedent that has amounted to nothing but increased aggression?
If a new approach works, good for all of us. If it does not, we are where Obama left us. Seems we are getting along better with N. Korea than we were 2 or 3 years ago.