TOKYO -- Although U.S. President Donald Trump's now famous Twitter invitation to North Korean leader Kim Jong Un on Saturday looked almost spontaneous, it seems he had always envisioned a Panmunjom handshake as the climax of his Asia trip.

Xi Jinping felt the G-20 spotlight shift away from him in Osaka last weekend and onto Kim Jong Un, Donald Trump and Moon Jae-in at Panmunjom. (Nikkei montage/Reuters)
Much-anticipated Xi summit was but an opening act for the North Korea crossing