It's always difficult to be sure about some concept or theory before it proves itself in practice.

That is a major issue with COIN theory; it does not seem to win a war. The successes always seem to be stuck on the local or regional a.k.a. tactical level.
Vietnam, Iraq, Afghanistan - there's no strategic success to be attributed to COIN theory.


(Iraq had in my opinion only a coincidence of COIN tactics and "surge" with dominating Iraqi factors such as people getting fed up with AQI & civil war and finishing the ethnic cleansing).

Maybe we should understand COIN theory as tactical instead of pretending that it's a recipe for strategic success.