So, we all know the news. In just a week, the situation in Korea has made yet another U-turn. A third Inter-Korean summit is planned, and an unprecedented North Korea-U.S. meeting appears possible. Pyongyang has indicated its willingness to talk and, for the first time since 2006, made a commitment to eventual denuclearization.

All these things are completely unprecedented, and it is quite normal to wonder "why is all this happening?" The answer is simple: like it or not, Donald Trump's policy has been remarkably successful – so far, at least.