Afghanistan - another Vietnam? How can we fix it?

In Afghanistan things seem to be worse than in Vietnam of the 60's. Unfortunately no Woodstock to follow. The problem is not that the US government is making errors - we all do. We are human - not divine. The problem is that after all this time, blood and money spent they haven't learnt anything. That's how it will look on the surface. Blame it on stupidity. That though will be naïve and irresponsible. The US government is not dumb - it is powerful. The only logical conclusion then will be is that is exactly what they want - an draining of US resources for the benefit of... I don't know who but tell me if you have any ideas?