Calwell's book is outstanding. He understood warfare between European/American forces and the less formally organized (to try to not offend the thin skinned) forces found in what is often referred to as colonial warfare.
What so many "historians" have failed to do is study and comprehend how these non-European style forces fought.
So many writers about the Little Big Horn would have been well served to have read Calwell's book before trying to say how Custer should have fought at the Little Big Horn.'
Custer did everything Calwell said should be done to achieve victory. Calwell did point out that every so often, it didn't work. And if it didn't work, the battle was not just lost, it was a great disaster for the European style force. To win against these forces required taking what would be considered foolhardy risks against European type forces. But that is what was necessary to defeat the enemy.
Calwell has countless historical examples. If one wants to really understand fighting Zulus, Sudanese, Pathans, American Plains Indians and many others, this book is a must. That is not to say that all of these various forces fought the same way. He draws the distinctions between them. But they all required a totally different approach than what most students of military history understand.
Tom