In an ideal world, the Eurovision Song Contest would be all about music and cross-border camaraderie. In reality, delicate diplomacy is essential to prevent politics from spilling into the annual glitz fest. A cast of hopeful artists from 26 countries will compete in this year's final on Saturday in Sweden, homeland of inventor Alfred Nobel, who gave his name to the famous international peace price.

Yes, those pesky giant pandas from Sichuan province are causing trouble again. Earlier this month, we noted that the media was hailing the arrival of Sweetie and Sunshine at the Edinburgh Zoo in Scotland as the latest chapter in China's grand tradition of "panda diplomacy,"...