Thailand has banned a textbook about the country on national security grounds, with the tome’s exiled editor saying on Thursday it was outlawed over its content on the Thai monarchy. The royal family holds revered status in Thai society and is shielded from criticism by a strict defamation law that critics say is used to muzzle dissent. The book, a second edition of the Routledge Handbook of Contemporary Thailand published in English in August, was edited by Pavin Chachavalpongpun, a prominent...