Callwell's approach, while relatively balanced given when it was written and for what purpose, still is, in Kilcullen's terms, enemy centric. This does not make it a bad book nor negate everything the author says. Trinquier's work, for example, is enemy centric and still valuable.

The USMC SWM clearly engages Callwell in a dialogue. It accepts two of his 3 classes of small wars but explicitly rejects his third - wars of conquest or annexation. While the SWM would agree with Callwell on some tactical approaches it is, by contrast, population centric. And, I would argue, after getting by some of its archaic politically incorrect language, most of its approach could be found within the new COIN FM.