The problem for me isn't that I can't do the home landings in Japan. With enough time, I can gain air superiority and para-drop my way into Nagasaki. The problem is that that usually takes too long and Japan joins the Axis powers (which doesn't make sense: Germany only "declared" against China because Japan was the stronger combatant). I don't want to have to wait for the European theater to finish, or worse, have to take care of things myself, when my war is over.