Also IIRC the Vietnam war is not considered to have been one of America's finest military successes, either.
Americans grew tired of Iraq when insurgents kept picking off a soldier every other day and there was little to show for their loss. Similar themes presented in the latter years of Vietnam, combined with a complicated political picture stateside. That's the success of an insurgency: attrition not of materiel, but the minds, resolve, and fortitude of a belligerent. That was certainly evident in Vietnam, as well, and it's a great parallel.
There really was ~zero progress (net; there were some wins and some losses) from late-2003 to early-2007 in Iraq, overall, and from ~2003 to ~2009 in Afghanistan (the 2009 end date is questionable; I'm reluctant to say Afghanistan overall is better right now than it was right after the CIA/ODA 555 operations in late 2001, as described in First In by Gary Schroen).
I was in Iraq watching this and was a lot more critical of the way the US was fighting from 2003-2006 than of the actual casualty numbers.
It's certainly more rational to be more willing to take a few hundred casualties if it brings a quick victory than to endure long slow bleeding of thousands, but I don't know if popular opinion is rational. I think casualties-per-second are much higher in offensive operations than in purely static defense, though.
I've lately come to the conclusion that modern warfare came into being because of Napoleon's genius and his wars of the early 1800s. He was way ahead of his time, and you could sense this by how "surprised" at his tactics were the guys confronting him from the other side (the Prussians, Austrians etc). For what it's worth, I think that WW1 which took place 100 years later was still an "old world" war.
What I'm trying to come at is that even Napoleon had to face a huge "insurgency" war in Spain (those insurgents will by today's standards be called "terrorists"). Even Napoleon couldn't "win" that war, I doubt it that in today's US military there are smarter heads when it comes to war.
The theory of the 'good guys' (the scare quotes aren't hedging, they're just being careful to avoid ideological framing of the discussion), Lind in particular, is rapidly adjusting to the new threat model. That was the thrust of my point to the other commenter here. There's an interesting parallel in that countering terrorism and counterinsurgency are largely reactionary by their very nature, and the 'good guys' have been left reacting to the new model of warfare in itself in, say, the last decade. People do disagree with Lind on fourth-generation warfare, for what it's worth.
We're "catching up," not "innovating" on the battlefield today. That's the big lesson here.