As the U.S. relationship with some traditional allies fractured during the second Trump administration, ties with Tokyo have only improved. Now, after they launched a coordinated intervention to strengthen the yen, the alliance seems to explicitly include backing for the Japanese currency.

“This intervention was a sign of friendship,” U.S. President Donald Trump told reporters on Sunday. “Japan has always been very good to us — with the exception of course of Pearl Harbor.” Raising the 1941 surprise attack seems to be his favorite Japan joke; it caused Prime Minister Sanae Takaichi to squirm during a visit in the Oval Office earlier this year.

But she won’t be too concerned about the optics if the U.S. delivers what she wants. The entry of the U.S. into Tokyo’s attempts to strengthen the yen decidedly changes the game.