When do we start the clock?

So a bunch of news sources are reporting today as the 70th anniversary of the outbreak of the Second World War. That is, 70 years ago today, the German Luftwaffe began bombing Polish towns and the Kriegsmarine shelled Danzig. Of course, Czechoslovakia had been annexed a year earlier, and before that the Nazis had supported the Fascists in Spain. Meanwhile, the real fighting between Germany and the Anglo-French allies would not actually begin until 1940 -- that's why it's called "The Phony War."

And in Asia, it's even more odd because while war officially started in 1937, the Japanese were invading Manchuria as early as 1931.

Indeed, American (though ironically very pro-Chinese) wartime propaganda like Why We Fight explicitly dates the beginning of World War II from the invasion of Manchuria, not Poland or even Pearl Harbor.

I'm certainly not offended by marking the beginning of the war this way -- Canada did, in fact, declare war on Germany because of the invasion that started this day. (The anniversary of the declaration of war will be the 10th, right before another auspicious anniversary.) But it's important to note that the war was raging before we joined the fight. Canadians love to mock the late American entry to the war -- and it's a privilege that I'm willing to earn by being similarly mocked by the Chinese and Spanish in kind.