The United States returned to Iran a 2,700-year-old silver drinking cup, looted from a cave in Iran and seized by US Customs officials a decade ago, NBC news reported. The cup is valued at a million dollars at least. … The cup, cast in the shape of a winged griffin, has been stored in a New York warehouse, since authorities seized it from an art dealer who was arrested trying to sell it. For years, US officials have been saying they couldn’t return it to Iran until diplomatic ties with Tehran were normalized. …