When Japan apologizes

Perhaps.  But as long as Japan's official attitude toward apologizing to America is variations on 'you had it coming', I'd say the apologies can wait.  I hate it for the victims of the war that Japan started, including those innocents killed at Hiroshima and Nagasaki.  But it was Japan's fault.  Besides, as I said here, if we do blame the US for using the bombs, then we blame the entire world that had embraced the philosophies of the age allowing the use of such things.  Things that, had Japan possessed the resources and ability to produce, it would have used in a fast heartbeat.  That the US was capable of doing what other nations gleefully would have done should say to us be careful about being coerced by the world into accepting the latest, hippest philosophies of the age.