[I]t's a far cry from what COIN advocates were saying a year ago. Then US/ISAF destruction of property was a bad thing because it "creates more insurgents." Today, destroying property, not such a bad thing because we helped the people whose homes were destroyed to rebuild them i.e. building trust. It's perhaps another example that COIN advocates tend to define COIN by whatever definition furthers their arguments at that exact moment.
The debate is currently ongoing on Twitter, where Foust observed that "From the outside, I have the sense that whatever soldiers do is being defined as COIN, regardless of action."
This is an analytical problem in addition to a policy one. First, "COIN" as we understand it is a very recent body of military doctrine. Although it has antecedents in 19th century military campaigns, it is essentially a Cold War-era form of military science that has crystallized (at least in US military experience) as a distilled product of certain 1940s-1970s French and British military experience. What it represents in practice vs. rhetoric is a loaded topic that divides historians and analysts. But it does, especially in the US reception of it, bear imprints of rhetorical Cold War anticommunism---both in the relatively liberal US conception and the messianic call to global war against subversion seen in Galula and Trinquierer.
"Countering irregulars"--i.e guerrillas, brigands, mad mahdis, and such groups is as old as warfare itself, a point frequently made by William F. Owen during Small Wars Council debates. COIN falls under this tradition, but the two are not necessarily interchangeable. COIN advocates make the argument that COIN doctrine provides a better route for countering irregulars than other, older methodologies. Their detractors disagree.
In practice, however, there is little analytical purity to be had. Moreover, even within the framework of one war many typologies of conflict can be observed--the US Civil War was mainly an interstate war with significant irregular components and proto-COIN elements. Adding another level of analytical noise is the political purpose of COIN doctrine. As Gulliver observed on Twitter, official COIN doctrine is often used as strategic communications either abroad or domestically. So things that aren't COIN are dubbed to be COIN and things that are COIN are assumed not to be because they do not mesh with a touchy-feely image sometimes put out.
To make things a bit simpler, perhaps it might be wise to point out that COIN is a very broad and ill-defined concept that also serves as a frame for Western conceptions of modern counter-guerrilla operations. It has room for tanks and human terrain teams. In many places around the world the conditions that Galula described don't really exist anymore. In the future we might not even use the word "COIN" to describe our operations.
What hasn't changed is the basics: a strategist trying to suppress a guerrilla movement should take note of the policy objective, the "facts on the ground," and the means available. History and theory can frame the cognitive space that guides this determination but not suggest correct answers. In short, give the Floating Clausewitz Head his daily allotment of burnt offerings.