Fast Nagatos and the Washington Treaty

What if Japan completed two more fast Nagato-class battleships before Washington?

The added ships would make Japan's accepted treaty limit much harder to negotiate, because asking it to scrap them risks crossing a national red line.

A true fast battleship had to keep pace with the scouting and cruiser line, pushing the Nagato design toward roughly 28 knots and greater displacement. Four such ships would leave Japan with about 70,000 extra tons to protect when the Washington negotiations begin. Forcing Japan to scrap Fuso and Yamashiro could cross a political red line and jeopardize agreement, while raising Japan's allowance also raises the entitlements claimed by Britain, the United States, France, and Italy. The speakers use the absence of a quantitative cruiser limit as another example of negotiators avoiding demands that a major participant would simply reject. Treaty design therefore depends on the fleets already in the water and on each state's willingness to walk away, not only on an abstract ratio.