There is no achievable victory in Afghanistan now. We got Bin Laden. We went from that and punishing the Taliban for harboring him being our goal to a goal that involves wiping out an ideology (which will never happen) and building up a modern democratic nation from something that was in the tribal stone ages before we got there.
What we went in to do was done a long time ago. No more wasted American lives on lost causes. No more endless wars. No more nation building, except when that nation is the United States of America.
Very well put. The argument for staying is thin to say the least.