Yes, yes, jamaksin... I am aware that Japan's aggression against China didn't first start in 1937 - but that is generally agreed upon as the year in which Japan geared up its activities and moved against China *in earnest*. It is not my intention to instigate a dispute with anyone over the actual starting date of World War II - I just think it rather western-centric to focus so much on the European theatre of war and September of 1939 when the article was about *Japan* and its military aggressions in Eastern Asia.
"Origins of the Pacific War", Keiichiro Komatsu, St. Martin Press, New York, 1999, [ISBN 0-312-17385-7], (from his PhD dissertation taken at Oxford).
A Japanese perspective perhaps worth a quick scan.