I don't think our government is afraid of the tabliban (except for the usual "we can't afford many deaths if we want to win next ellection") What they are really afraid of is looking like "bad, militarist, aggresive" people. You know, they've been trying for years to convince people that our armed forces are actually some kind of "proffesional boy scouts" whose job is putting out fires, helping in situations like Haiti and this kind of things. And, of course, shooting at anyone (even if this anyone is a mass murderer terrorist) might be harmful for this fairytale picture they want to show us.