The counterfactual's central premise is deliberately implausible. Roosevelt's sympathies lean toward China and Britain, while American isolationists want to avoid war rather than fight beside Japan. An openly fantastical intervention replaces the political alignment that actually existed. This allows the discussion to test how a much broader war would alter the naval balance without presenting the premise as probable history.
Chapter · 42:23-44:56
A deliberately extreme U.S. alignment
An American government joining Japan is the scenario's most unlikely premise and the only alignment that gives Japan a serious chance.