Would other navies demand ships after an early Italian challenge?

Would the Americans or Japanese demand modern replacement ships as compensation for additional British construction?

They might ask, but the projected outcomes differ. American funding remains uncertain, Japan's claim is judged weaker, and France would have a direct need to respond to Italy.

Allowing Britain extra ships in response to an early Italian programme raises the question of equivalent American and Japanese demands. In this counterfactual, American construction remains dependent on securing funding, while a Japanese request is expected to face resistance. Britain's proposed negotiating position rests on Mediterranean security and the threat that withdrawal could undermine the treaty system. France would also need to answer the Italian ships despite the expense. An earlier French programme could bring dockyard expansion and its initial difficulties forward, giving time to resolve them before later construction. That would change the timing of the work without necessarily making it cheaper.