Borodinos complicate Japan's treaty calculation

Would Japan accept the Washington Naval Treaty while completed Borodinos remained outside its limits?

Possibly, because the economic case for a building holiday remained strong, but Japan would want the Soviet ships covered by the negotiations.

The economic incentive for Japan to stop an expensive capital-ship race would remain powerful. Completed Borodinos would nevertheless create a regional threat outside the treaty if the Soviet Union did not participate. Soviet modernization or a new follow-on battlecruiser could then compel Japan to upgrade its own force. An arms-control agreement is only as stable as its treatment of the navies that matter in each signatory's theater.