One of the biggest problems with the United States at this point in time is the fact that most of its historiography--and, most significantly and worryingly, its military historiography--is the property of folks who tend toward the right wing of the political spectrum.
I suppose this does make a certain amount of logical sense. Historiography, almost by nature, is the domain of those with sufficient education and leisure to make the study of history a lifelong pursuit. People with that kind of education and leisure tend to be from the upper classes, and the upper classes tend to be the old-school conservative classes. (Now, I know these are generalizations. I know this does not hold true in all cases--the fact of having money, education, and leisure doesn't automatically equal political conservatism. However, it's my biased and incomplete judgment that this is, for the most part, true.) And those who write military history tend to be people who have an interest in the military--and let's be blunt here, the military mindset isn't one that rewards independent inquiry, questioning authority, criticizing tradition, etc.
The practical upshot of all this is that people who write history books tend toward, at the very least, centrism if not up-front conservatism. (I realize this is a somewhat controversial assertion, since conventional wisdom nowadays seems to be saying that ever since the 1960's, a small cabal of out-of-touch ivory-tower radicals has hijacked the field of American history to push its own self-centered agenda (see, for example, Larry Schweikart's A Patriot's History of the United States).) And that people who write military history works, particularly those dealing with American military activities, tend either towards gee-whiz pseudo-pornographic examinations of weaponry and/or technology and/or esprit de corps (Thomas Ricks and Victor Ruggiero, I'm looking at you), or efforts to portray American military activities as high-minded unambiguously noble crusades (Stephen Ambrose and Victor Davis Hanson, I'm looking at you).
So, that's my view of the situation as it is now. Here is my argument for why this is bad. Those who write history are the ones who dictate the public view of the past. This effect becomes more pronounced the more time passes between the event and the present day. The United States is a nation that has self-consciously rejected history; while, as in Emerson's view, this can be a good thing (e.g., it gets rid of old prejudices and cultural antipathies--the United States is a place to make your own destiny anew without being beholden to your past, in this view), more often than not, it is bad (e.g., the majority of American citizens don't know or care about the past, and therefore will believe without critical examination what "historical authorities" tell them about the past).
Here's an example. In the 1970s, conventional historical wisdom said that the war in Vietnam was a criminal waste of money, life, and national idealism, and that the hippie/civil rights/feminist movements were the new American heroes bringing us into the new age. Today, people who write history books are asserting that not only was Vietnam not a mistake, it was a moral obligation on our part. The hippies and feminists, by contrast, are not remembered for their ideals or even their actions--rather, they have gone down in history as silly, unwashed, unshaven, shrill empty-headed slogan-spouters. It is with great glee during the 1980s that newspapers and magazines reported on, say, Angela Davis spending $200 a month on afro maintenance, or on any other former radical who made a great deal of money during the Reagan years. Nobody remembers what these old hippies did or said, what they stood for; nobody remembers their rebellion against a social order they felt was intolerable. All people remember nowadays is the trappings. Kids today will wear a peasant top or hempen sandals, but they have no idea why people wore them thirty years ago--they want the look, they don't want the politics.
As for military history, the books about old campaigns tend to be the ones that portray the American military as unambiguous winners. Vietnam, they tell us, was a war we could have won--if those doggone liberal elitists/cowardly politicians hadn't stabbed these decent American Fighting Men in the back by not supporting them. Never mind that the military was ill-prepared and ill-equipped to fight the kind of guerilla warfare that the Viet Cong waged; never mind that Vietnam had wanted to be free of Euro-American influence ever since the French arrived in the 18th century; never mind that the South Vietnamese government was corrupt and tyrannical; never mind that we had no clear-cut reason for being there in the first place; never mind that, as with Iraq thirty years later, our rhetoric was writing checks our realpolitik couldn't cash. No, we only lost Vietnam because the people in power were effeminate cowards. (I leave it to the reader to research who asserted that the only reason Germany lost the Great War was that the honest and courageous German rank-and-file had been "stabbed in the back" by the people with money and power.)
My point, after all this rambling, is that more leftists need to be more involved in history, particularly military history. I know a lot of leftists tend to shy away from reading about military subjects, either through boredom, or because they get turned off reading about bloodshed or troop movements, or because they feel their own pacifistic natures will be corrupted via reading about war. I submit that this is a mistake. Military history, now more than ever, needs a leftist perspective, and needs one desperately.
Because, from a military standpoint, the finest hours of the United States have been motivated by at least a moderately liberal sentiment. Between Concord and Yorktown, the United States shattered by force the idea of the divine right of royalty. Between Manassas and Appomattox, the United States, at least temporarily, conquered an aristocracy that treated human beings as property. Between Normandy and Berlin, and between Guadalcanal and Iwo Jima, the United States destroyed governments of extreme nationalism and racial supremacy. To be sure, this is an extremely simplistic interpretation of history, and one that isn't supported by events subsequent to these examples. But there's an underlying truth there--and one you wouldn't notice from the "conventional" histories.