The conflict Hostile_encounter led to Causation a recorded Recording 20.77 million population reduction Cause_change_of_position_on_a_scale in Shaanxi and Gansu occurred Presence due Causation to migration and war-related death Death .

It accounted for the majority of civilian and military casualties in the Pacific War , with between 10 and 25 million Chinese civilians and over 4 million Chinese and Japanese military personnel dying from war-related violence , famine , and other causes .