LONDON—In a meeting to discuss possible adjustments to steel import tariffs, Prime Minister Boris Johnson confided to his cabinet Monday that he was unsure how the United Kingdom was one country but also four. “Just to digress for a moment, I’m still not entirely wrapping my head around how our country is also four countries—that doesn’t really seem to make sense, does it?” said the prime minister, informing the entirely silent room of chancellors and secretaries that he would appreciate some clarification on a few follow-up questions, such as whether the Queen ruled all of it or that was only England. “It just doesn’t seem reasonable to have a country inside a country. What does the word ‘country’ even mean if you can do that? Also, Canada is part of British Commonwealth, right? So does that mean I’m in charge of Canada? Or did that change after the Brexit thing? Did we even do that?” At press time, Johnson had broken down completely after remembering about Wales and deciding none of this was worth understanding in the first place.