Anyway, today Steven Den Beste takes exception to this MeFi thread commemorating the date of August 6:
Why do lefties commemorate August 6, but not March 9 (the firebombing of Tokyo)? Why not September 18, 1931, when the Japanese army manufactured an "incident" to justify the conquest of Manchuria? Why not July 7, 1937, when another "incident" at the Marco Polo Bridge outside Beijing led to the second Sino-Japanese war?
The traditional date for the beginning of WWII is September 17, 1939, when the German invasion of Poland began, but some historians have argued cogently (IMHO) that WWII actually began either in 1931 or in 1937 on the dates given above.
And the Japanese were responsible for far more civilian deaths in China than the US ever caused in Japan.
Why do enlightened and compassionate lefties not commemorate those dates? Of course, the answer is obvious: because those are not days of shame for America. But that still doesn't explain why August 6 is commemorated but not March 9.
First of all, I think SDB's got his dates slightly wrong above: Germany invaded Poland not on September 17, 1939, but on September 1 of that year. September 17 is when the USSR likewise invaded Poland (more detail here). I also think that WWII, understood as a conflict that arose out of the unresolved problems of WWI, really began when Germany invaded Poland, but that's neither here nor there: good arguments can be made for the war actually beginning with Japan's invasion of Manchuria.
But anyway, SDB asks in the MeFi thread why August 6 should be specially commemorated when the firebombing of Tokyo should not. The answer is, of course, that August 6 involved the use of the atomic bomb.
I'm pretty much of a political lefty, but even so, I've never believed that dropping the a-bomb constituted a war crime, nor have I ever believed that Japan was on the verge of surrender anyway. (If that were true, it wouldn't have taken a Nagasaki to drive the point home.) I don't believe that August 6 is a "day of shame" for America. I don't think it was a moment of greatness or heroism, either. It was a day when President Truman took the best of a couple of crappy options before him.
Why commemorate August 6 over March 9 (the firebombing of Tokyo in 1944)? Because of the atomic bomb, obviously. Like it or not, that was an iconic event in world history. Regardless of the numbers of dead (the Tokyo firebombing claimed more lives than the Hiroshima bombing), the use of an a-bomb representing an upping of the ante. As of that moment, destruction on a comparable scale with Dresden and Tokyo could be accomplished not with several hundred bombers dropping tons of incendiary explosives, but by a single bomber dropping one bomb. As of that moment, it was possible for a country with an atomic bomb to wreak tremendous destruction with significantly less effort. That's why the date is an important one in history. At least to me, it is.
Hiroshima still resonates today because nobody worries about al-Qaeda firebombing new York City. But we sure as hell worry about them getting hold of a nuke, don't we? Sure, Bin Laden could do worse with five hundred B29's laden with thousands of tons of incendiary devices than he could with one a-bomb in a suitcase, but what's the scenario that really scares us?