To say it was a whole watse of time is offensive to those who payed the ultimate sacrifice. It wasn't, we achieved or main effort which was to put a massive dent on global terrorism. We achieved that. After that it was our intent to make that country self dependent against their own integral threat.
As I said before, you can't win a counter insurgency war. You are fighting an idea and not an enemy. You kill 2 insurgence and 5 take up this ideology through revenge. You miss place a fire mission and a whole village changes. Hearts and minds went a long way to stop this, which is why those people did not lose their lives for no reason.
We had to leave, billions of pounds later and probably trillions of american dollars, the best training in the world, and they bottled it. Since 2014 our main effort has been to mentor and advise their military in strategic military operations. It has been their fault not, a god damn thing we could of done any better.
We knew we were leaving Afghan in 2018 the last tour was supposed to be in 2020 potentially 2021. Our withdrawal has been fine. The Americans on the other hand....