The biggest war in history was this one involving 61 countries & more than 110 million soldiers
However, Mao sent more ethnic Korean PLA veterans to 
Korea and ... his war plan to involve general attack across the 38th parallel, 
rather than a... [DOC] [TLE] Military history of Australia during World War II - Wikipedia [PAR] Australia entered World War II shortly after the invasion of Poland, declaring war 
on Germany on 3 September 1939.