Could Britain, Germany, and Japan form a tripartite pact in the 1920s?
Short answerIt is possible, and Britain and Germany might each moderate Japan through different military relationships, but the effect is uncertain.
NotesThe viewer carries the early-peace scenario into the 1920s by proposing a British-German-Japanese pact. The arrangement is interesting because Germany could be an important partner for the army while Britain remains the key naval partner. Those two relationships might give both European powers leverage to moderate Japanese policy. The pact remains a plausible but highly contingent branch of the counterfactual, with no certainty that it would form or restrain Japan effectively.