So, in other words, as things stand, we really can't win one of these wars with our hands tied, our backs have to be up against the wall like WWII. That's part of the problem alright. That's why we nation-builded.
Though Iraq, imho, was a won war, is won again. Iraq succeeds, Afghanistan, work-in-process.
And yes, Afghanistan has almost an endless supply of fighters, many foreigners not just the Pashtuns.