Where things begin to get complicated is where people start dragging their opinions into the matter and trying to see inside the heads of dead people who didn't set down their thoughts for posterity. Does the Sino-Japanese War that started in 1937 constitute part of World War II? Chinese historians in the PRC and Taiwan apparently don't think so, and by the same token Finns don't regard the Winter War against the Soviet Union as part of the big throwdown either. Traditional histories of the war tend to leave both of those wars out of the metanarrative as well. Is this because traditional histories tend to focus primarily on the actions of the major powers while ignoring the bloody sideshows around the perimeters? Yes. They do this for a very good reason: damned few of us have the time to wade through the sixteen-volume Official History of the United States Navy in World War II, no matter how readable it might be; still less do we have the time to do the same for every service of every nation involved, even assuming that we could actually read Chinese, French, German, Italian, Japanese, and Russian (to say nothing of Finnish, Greek, Norwegian, Portuguese and Spanish) and that official histories had actually been written that didn't conveniently gloss over the awkward parts. (Just try finding some honest accounts of the Second Shock Army's experiences in the official Russian/Soviet histories!) You have to pick and choose what the important things about the war are, and be ready to defend your choices. This is true of all history, regardless of what part of it you're looking at.
Trying to fog the issue by nattering on about metanarratives and examining them to see who is privileged and who is snubbed does nobody any good unless you have good reason to believe that the metanarrative you're examining is in fact a tendentious, lying piece of revisionist garbage that deliberately sets out to make people believe something that isn't true. For example, it is a fact that quite a few non-Germans joined units of the Waffen SS in order to fight Communism. To expand this fact into a thesis that the entire Waffen SS was some sort of noble band of Teutonic Knights and a precursor to NATO is not only factually wrong but an assault on the profession of history and should be treated as such. The same, of course, is true of similar claims on the other side of the aisle regarding what kindly old Uncle Joe was up to when he was playing footsie with his good friend Adolf before the Great Patriotic War suddenly and inexplicably (yet gloriously - eventually) happened.
Postmodernists need to give over their folly and do some honest work in the groves of academe. There's a lot of thorny, poisonous underbrush that's grown up there in the last forty years, and they could do us all a service by weeding that crap out instead of wasting their time theorizing about this and philosophizing about that.
(Via the History Carnival, through Instapundit)