It’s best never to take White House press secretary Karine Jean-Pierre’s word for anything, but we can presumably believe her when she says the flying objects the United States shot down in recent days aren’t from an alien civilization. Although she left herself some wiggle room — “there is no indication” of extraterrestrial activity, she said, displaying the weasel-word instincts of someone whose job involves dancing around the truth. If she’s wrong, we are having close encounters of the most unwelcoming kind, as our alien visitors learn more than they presumably wanted to know about the business end of the...