The world turns even if America doesn’t. That’s certainly true on trade, where a rebranded Trans-Pacific Partnership has begun with the new year in 11 countries two years after President Trump withdrew. The biggest losers are American producers.

The CPTPP, as it’s known, entered into force in Canada, Japan, Mexico, New Zealand, Australia and Singapore last week, where it will slash 95% of tariffs on goods among its members, which account for 13% of global GDP. The others include Vietnam, where CPTPP is in force Jan. 14, and...