North Korea caused the flipping of a million dictionaries when it ridiculed President Donald Trump as a “dotard” just over two years ago. Since then, at the height of Trump’s war of words with leader Kim Jong Un, personal relations seem to have improved between them—until now. Trump revived his “rocket man” nickname for Kim in comments made on Tuesday during a visit to London, and North Korea has now retuned in kind. Choe Son Hui, the first vice foreign minister, said Trump’s remarks “prompted the waves of hatred of our people against the U.S.” because they showed “no courtesy when referring to the supreme leadership of dignity” of North Korea. She went on to say she suspects Trump is slipping back into being a dotard—which, if you’ve forgotten, means an incredibly old person who is losing their mental faculties. She said: “If any language and expressions stoking the atmosphere of confrontation are used once again on purpose at a crucial moment as now, that must really be diagnosed as the relapse of the dotage of a dotard.” Trump should consider himself warned.