I think the cowardliness is shown with the IEDs your countrymen have buried all over the place killing your own people in the process. It's also pretty cowardly to taunt the US soldiers with gunfire hiding behind women and children with a camera waiting for return fire, so they can use it as propaganda that the US is evil.
IF the US was as evil and unscrupulous as you say we are, we would simply go from town to town and systematically kill each and everyone of you like the Russians were doing before we gave you weapons to stop their gunships. If we failed at anything, it was supporting Pakistan the whole time they were supplying and protecting the Taliban, (Pakistani ISI) to keep power over Afghans. In a nutshell, your country that is so invisible has already been conquered by Pakistan. We gave it back to you, but your countrymen are weak and will more than likely surrender to the Taliban yet again once we leave.