Exposed treaty eavesdropping could collapse the naval settlement

What if Japan discovered American eavesdropping during the naval treaty negotiations and walked out?

The disclosure could alienate Britain as well as Japan and allow US political support to shift before talks resumed, collapsing the treaty system.

The counterfactual begins with Japan discovering that the United States had monitored its naval treaty delegation. A Japanese walkout would make Britain suspect that its own delegation was also compromised. By the time Japan returned after the Kantō earthquake, American political willingness to fund or renegotiate the settlement might have changed. The treaty process could therefore collapse instead of resuming where it stopped.