In the age of aggressive ‘wolf warrior’ diplomacy, warm words from Chinese officials about the U.S. are a rarity. Yet Huang Ping, China’s consul general in New York, was unusually effusive after hosting a ceremony last month to celebrate the return of two 7th-century stone carvings to his country, writing on Twitter that the move would “bring positive energy into China-US relations.” Whether the return of the carvings depicting Zoroastrian demons — that had been on loan to the Met