I'm not really certain what his point is. Do we need to do some more thinking about lessons learned? Sure.

But he also seems to be saying nobody can ever beat an insurgency. OK, so abject surrender? Do we concede the world to ISIS?

If you talk about a problem without discussing solutions, it's called "whining." If Professor Russell wants to assert that conventional forces can't win, SOF can't win, then he should suggest alternatives. (And by alternatives, I don't mean the stale, socialist/Communist bromides that failed so miserably wherever applied.)