Styles editor Stella Bugbee wrote a lovely essay on why we — Musk included — are all so obsessed with the letter X. “For marketing purposes in the 1990s, X had a certain cool.

Indeed, Mr. Musk seems to have something of a fixation with the letter X. He named his rocket company SpaceX, a Tesla the Model X, and one of his own children X Æ A-12, or X for short.

The duties threatened in the letters effectively match the initial reciprocal tariffs Trump briefly imposed on the countries ...