What if the Allies had captured Napoleon, Hitler, Stalin, or Japan's emperor in a leadership-decapitation operation?
Short answerThe result depends on legitimacy and succession: Hitler's removal might aid negotiation, but seizing Japan's emperor would likely harden resistance and make peace more difficult.
NotesAbducting Hitler in 1944 might create an opportunity for senior German army officers to negotiate while Nazi leaders fought over the succession. Göring and Himmler are identified as likely rivals in that struggle. The same intervention against Japan's emperor is expected to strengthen resistance by giving hardliners an affront to national honor around which to rally. In that scenario, taking the emperor would make peace harder to achieve and could encourage desperate civilian resistance. Napoleon raises a different, unresolved question because his regime depended heavily on his personal authority.