Except that is exactly what they did.

Via RCP:

HAGEL: First of all, we didn’t negotiate with terrorists. As I said and explained before, Sergeant Bergdahl is a prisoner of war. That’s a normal process in getting your prisoners back, that’s first. Second, we are dealing with terrorism and hostage taking all the time everywhere. I think America’s record is pretty clear on going after terrorists, especially those who take hostages, and I don’t think what we did in getting our prisoner of war released in any way would somehow encourage terrorists to take our American service men prisoner or hostage.