The U.S. government has banned American government personnel in China, as well as family members and contractors with security clearances, from any romantic or sexual relationships with Chinese citizens, The Associated Press has learned. Four people with direct knowledge of the matter told the AP about the policy, which was put into effect by departing U.S. Ambassador Nicholas Burns in January shortly before he left China. It’s not uncommon for American diplomats in other countries to date locals and even marry them.