Is victory in Afghanistan Achieveable?

The NATO ISAF coalition has been in Afghanistan for nine years, in that time we have lost hundreds of troops, and possibly 10s of thousands of civilians. to me there seems to be a parrallel between this war and the soviet invasion in the late seventies to late eighties. The Russians left after 10 years with thousands of their soldiers dead and a bloody lesson learned. The Russians even warned the American's of how the CIA funded mujahadeen would turn on their sponsors, but the US would not listen and after the tragic events of 9/11 America launched a war on the taliban in Afghanistan. nine years later we are still fighting the same invisible enemy, who can disappear into the environment in seconds, so I have a question, can we defeat an enemy who does not fight conventional warfare, and who knows the land like the back of their hand and has such commited belief that what he is fighting for is right. answers are all apreciated