A few days ago, I put one of my college-age children on a plane to Berlin, on the way to a month-long theater intensive. It was a wistful and exciting moment, a rite of passage for many privileged middle-class parents around this time of year. It felt like the kind of experience that’s supposed to remind you, amid the relentless passage of time and the chaotic info-jumble of contemporary life, to try to be fully present wherever you are. (I wouldn’t say that’s my very best skill.) I mention the obvious class privilege behind that moment not to cover myself in sackcloth and ashes, but on the way to a different observation. During our slow drive through heavy traffic to JFK, we talked about the ironies of international travel at this dire historical moment, when the U.S. has come visibly unstuck and the world’s long-running romance with America is well and truly over. I’ll be joining both my kids in Europe later this summer, and we half-jokingly suggested, while breathing the foul air of a …