It has been a failure. It is widely known as a failure here in all circles from left to extreme right/ultra conservative in (ally) Japan. They know about the North better than anybody in the states, having to deal directly with their threat, why cannnot you take it from Japanese conservatives for example that this template has not been working and will not work, hence Kim returning to bellicosity and trying another shakedown of the US which he and his predecessors have been doing incesssantly for decades.
I guess this is where I am supposed to ask what would you propose.