There are several million dead people in Manchuria & China would would beg to differ. WW II is generally acknowleged to have begun with the Japanese actions at the Marco Polo Bridge.
Actually, that is a comment I would completely agree with and I almost pointed this out - actually I did in my first post repeated below. However, I would question that it is "generally acknowleged" that WW2 began in Manchuria in 1931. Europeans certainly don't make this connection, taking the rather Eurocentric view that it is all about Hitler. That is why the best way is to describe "WW2" itself as beginning in December 1941 when Japanese aggression against the US, Britian and Dutch east indies, coupled with Hitler's declaration of war on the USA linked the 1939 European and the Sino-Japanese regional conflicts into a single world war.
"It also depends on what one means by "WW2". Arguably "WW2" did not begin until December 1941 with Japanese attack on the British and US in the Pacific. Prior to that, there was: (1) a European War which began in 1939 and a Sino-Japanese war begun in 1931 (or 1937 depending on how you define things)."