The address on the letter is the real story

Last week more than 1,100 of the people actually building frontier AI — rival labs who agree on almost nothing — signed one letter asking for a brake. What almost no one has noticed is where they sent it. They wrote to Washington. They did not write to Brussels, and they did not write to any multilateral body. Today's Call is what that single choice of address sets in motion over the next eighteen months, and who is quietly about to be left out of the room.