@Scisca
You're almost expressing a kind of Stockholm syndrome in that you seem to believe that the Nazis had turned the corner and came to respect the Polish people. I think the problem is that you're looking at Germans today and thinking they had a similar mentality during WW2.
In any case your claim that Russians didn't liberate your country is playing semantics. Did they or did they not force the Nazis out of your country?? And do you really think that you would have even existed as a Polish nation if the occupation turned permanent and colonisation began.
I am not doubting that crimes happened post world war 2 in your country but this in no way detracts from the absolute truth and fact that it was the Soviet Army that forced the Germans and their allies out of Poland and then allowed for a Polish republic to exist without absorbing it as they could have done as per the spoils of war.
And finally regarding your very crude interpretation of the world being better off without certain people if I was to use your same flawed reasoning I could make the same argument regarding Poland. I would say that both Russia and Germany would be better off if it didn't exist and they absorbed its territory. Ofcourse that would be a wrong assertion to make and I hope you can grasp how bad your argument is.
@OP
Japan is under full US military control and hence can't act without the permission and consent of the US with regards to China. I honestly think this will be resolved peacefuly because there is too much to lose. Having said that though Japan has to be careful not to overplay its hand. While they are allied with the US they can't afford to be reckless and they should do their best simply to maintain the status quo.
With China they are a proud and powerful nation on the rise and with that power comes more asseriveness. Having said that China will be best served to continue its economic policies and not to get carried away militarily at least for another decade or so.
