Speaking of TNR, Alan Wolfe has a great short post at Open University on Tet revisionism and its applications to the Iraq debate. In short:

This analysis is nonsense on stilts. There is no "military" theatre over here and "psychological" campaign over there. If insurgents convince Americans to withdraw their troops, they win the only military skirmish that matters. The notion that we "won" the Tet offensive is designed to keep alive the dangerous illusion that Americans never lose wars. In fact, we lost Vietnam and we are clearly on the cusp of losing Iraq. We could not win in either case because the people we were fighting against were able to mobilize more overall resources on behalf of their cause than we were on behalf of ours. Clauswitz would have understood. Tom Friedman does not.

Yes, right, exactly. I could recommend almost endless reading on the basic Clausewitzian point here and, damnit, perhaps I will.

It starts out with Clausewitz's classic book On War home of the famous aphorism that "war is the continuation of politics by other means." There's actually a very good reason why Clausewitz is so famous and why this line, in particular, is famous. "Politics" in contemporary usage tends to denote "partisan politics" or "electoral politics" so perhaps it's better to think in terms of the word "policy." The point here is that going to war, prosecuting a war, continuing a war, ending a war, etc., are all policy decisions. They are policy decisions undertaken to achieve policy goals. The goal of the VC/NVA military campaign was to persuade the United States of America to stop backing the Republic of Vietnam regime in order to precipitate the collapse of the ROV government and unite the Vietnamese nation under the leadership of the Communist government in Hanoi.

The Tet Offensive did not, on its own, accomplish any of those things. It did, however, achieve major strides in that direction. It was, therefore, a success. It wasn't a "military" failure but a "political" success, it was just a success. There are no military failures that succeed politically, nor military successes that fail politically. All military operations are policy initiatives, and the only criterion for success or failure is success or failure in achieving policy objectives.

It's certainly the case that policy objectives are sometimes achieved by utterly crushing an opponent's military establishment. This is, if you can pull it off, a pretty good way of convincing an opponent to agree to your policy demands. But, obviously, North Vietnam was a tiny country and never had any chance of crushing the entire American military in the way that the US, British, and Soviet militaries crushed the German, Italian, and Japanese militaries in the second world war. Thereofore, the North Vietnamese and their allies never tried to destroy American military power as their method of persuasing the US to withdraw from Vietnam. They didn't "fail" at this "military" goal but magically pull a "political" success out of their asses. Instead, they employed military tactics well-suited to the objective situation and succeeded in achieving their policy aims.

The United States of America has, however, a somewhat unfortunate national culture that's sharply averse to seeing war in this way. We've developed a strong preference for seeing "going to war" as a policy decision at which point "politics" stops and "war" begins, with "winning militarily" as the goal of the "war" phase. The development of this mentality, and its strengths and (considerably) weaknesses is outlined in Russell Weigley's classic The American Way of War: A History of United States Military Strategy and Policy which is, unfortunately, a not-very-readable book.

As Jeffrey Record points out in his (not coincidentally, similarly titled) essay "The American Way of War: Cultural Barriers to Successful Counterinsurgency" this frame of mind is uniquely troubling when the United States finds itself in "unconventional" wars.

You see this not only in the conduct and discourse of war supporters, but in some characteristic modes of criticism. The oft-repeated phrase that Bush had a "plan to win the war" but lacked "a plan to win the peace" is a manifestation of the same problem. Wars are undertaken to achieve policy goals. The policy outcome of a war is determined by the state of the peace -- the end of the war. If you don't have a plan to achieve your objectives, you don't have a plan to win the war at all. When you invade Afghanistan and manage not to achieve most of your key objectives -- the capture or killing of the al-Qaeda/Taliban leadership and bringing the entirety of Afghan territory under the control of anti-al-Qaeda forces -- you didn't "win the war" but then screw some stuff up. You lost the war. If your goals in Iraq were to (a) eliminate Saddam's nuclear program, and (b) construct a stable, pro-American regime in Iraq, and it turns out that Saddam had no nuclear program and you can't construct a stable, pro-American regime in Iraq, you've lost the war.