"Else China will make Japan accountable for WW2 atrocity."?  Calm down Tom.  What was Hiroshima and Nagasaki and the International Military Tribunal for the Far East?  The Japanese militarist leadership that prosecuted that war was held accountable, as were many Japanese civilians.  Its over.  It was over 72 years ago.  Anything that Communist China tries to hold over Japan today is a deflection of the CCPs human rights abuses against others (hello, Tibet? to say nothing of its role in the Cambodian genocide by supporting the Khmer Rouge) and its own people.  Japan and America, in the contemporary era, are two allies and democracies.  I hope that one day the "face" that China presents to the world comes from democratic Taiwan and those people in Hong Kong not corrupted by the CCP.