If you look at what an average Taliban volunteer soldier is you have a man or woman who for whatever reason has a grudge against the U.S. or NATO. It doesn't really matter the reason they are angry enough to go beg, borrow, buy or steal a Kalashnikov rifle for under $40 plus bullets and they are ready to go.
However, if you are an American soldier the government has already spent at least $500,000 to train you, feed you, medical care and pay even before sending you to Afghanistan and then if you get injured or die 85% of the time it is to an IED that is remotely detonated with a cell phone specifically the moment your Humvee drives over it and it is sure to be shape charged to do maximum damage.
This is not just about blood and death which is awful and horrific. This is a war that is bankrupting or some say has already bankrupted the U.S. and its allies. Even China is losing money right now on the 800 billion dollars it has lent to the U.S. and since its Yuan is tied directly to the value of the U.S. dollar for richer or poorer the value of not only our currency but their currency is in literal free fall. No one is benefitting from all this but Chinese exporters who might be able to sell more goods to Europe and other places with more highly valued currencies.
So, this war is financially one that we have already lost.
What is the answer?
I believe part of the answer is in hiring a mercenary army that the U.S. and NATO pays from Afghanistan or whatever country Afghans would least likely want to kill. The first choice would be Afghan troops trained by NATO and the U.S. NATO and the U.S. could pay them slightly more than their home country pays them and they could be commanded from Captain on up by American Special Forces officers. If an action was too hard for them then U.S. Special Forces could be sent in to finish the job.
In this way we would stop losing so many American troops that are so valuable both to the nation personally and financially through training and pay. So the grunt more and more would be foreign born and a mercenary paid by the U.S. and NATO and all other interested countries and parties and the U.S. and NATO countries could stop going bankrupt in this never ending war.