How many US soldiers does it take to apprehend/eliminate one al Qaeda operative?

There are not many things about afghanistan that justify us not vaporizing the place. Our "allies" are duplicitous drug dealers and the people are too utterly backwards to permit a real state to take hold. I mean, the place is controlled by tribes! Let's pull our guys out and hit the old nuclear reset button. Does it matter if we turn a stone age wasteland into a wastier-land?