Why do y'all care about the Euro? You make more money from tariffs on wine and cheese and other old stuff when it is strong. Kind of a 180 on policy?

Weaken the dollar: incentivize local production.
Weaken the Euro: incentivize imports of "inferior stuff" you don't need.

I don’t understand why Korea indirectly. I thought they were allies!

The goal appears to be helping Japan without sending a broad weak-dollar signal, and reducing the risk that Japan sells Treasuries, which could push 10- and 30-year U.S. yields, already near pre-2008 financial-crisis levels, even higher.