A must-read from H.R. McMaster, perhaps the outstanding soldier of his generation.
Here's a key point from near the end critiicizing the "revolution in warfighting" fad that afflcited the Rumsfeld-era Pentagon (emphasis added:
Emphasis in planning and directing operations, therefore, ought to be on effectiveness rather than efficiency. The requirement to adapt quickly to unforeseen conditions means that commanders will need additional forces and resources that can be committed with little notice. For efficiency in all forms of warfare, including counterinsurgency, means barely winning. And in war, barely winning can be an ugly proposition.