New Delhi, Oct. 29 -- Kim Jong Un, North Korea's dictator, rarely travels abroad. So his surprise visit on October 24th to Dandong, a Chinese city that borders North Korea, deserves attention. Mr Kim is rebuilding ties with China after four years of cosying up to Russia (by sending it troops and supplies for the war in Ukraine). He may also be preparing for new diplomacy with America, and possibly a meeting with President Donald Trump in November.

The official purpose of Mr Kim's latest visit was to commemorate China's entry into the Korean War in 1950 to support the Communist North. China and North Korea are playing up their wartime solidarity. This year is the 65th anniversary of their "friendship" treaty, a mutual-defence pact. Still,...