I forgot to mention a key part of my "plan": The U.S. would have spent much money improving the lives of Afghanis, building schools, hospitals and roads. They would have presented a giant Carrot instead of a Stick. This would have enabled the people to progress, gain confidence, and reject the Taliban.
How much money? Much less than was wasted on stupid military adventures there.
The only way this enlightened plan would have had a chance in Hades, would be if the US parked about 250,000 soldiers within the country AND secured the insanely rugged border with Pakistan. Even at our peak military body count, it still wasn't enough to properly suppress the Taliban... To get rid of the corrupting influence of contractors, it would take that many soldiers. And at 250,000 soldiers, the long term borrowing of National Guard and reserves would have been nearly impossible over the decade this would probably take. So, how to scrounge up so many soldiers for this occupation... Ergo the political problem the Shrub faced and solved by putting the war on Uncle Sam's credit card, pouring money upon contractors, and abusing the intent of the guard and reserves over the years...