FTA:

"The challenge is that ultimately this is a ground war, so air power is only useful to the degree that it helps support ground forces," said Seth Jones, a counterinsurgency expert at the Center for Strategic and International Studies. Afghan ground forces have suffered heavy casualties in recent months. Since 2015, when local troops took over combat operations from the U.S. and NATO, nearly 30,000 Afghan soldiers and policemen have been killed, President Ashraf Ghani recently revealed.

That pretty much sums it up.