During the debate on whether Obama should apologise for the US atomic bombing of Hiroshima and Nagasaki, as well as some people making trolley problem style comments about how many would have been killed had the atomic bombing not happened, others have argued that Japan has not shown sufficient acknowledgement of and/or contrition for its wrong-doings in World War II.
Within a broadly deontological (duty-based) framework, is offering an apology generally to be contingent upon a harmed party's acknowledgement of, or contrition for, its own wrongdoing?
(Disclaimers: This is assuming that an entire nation can be a harmed party or a wrong-doer, and it's also assuming that apologising won't cause Japan to commit harmful acts in the future.)