I know it's kind of an elementary question to be asking, but so is my knowledge of that part of the conflict. Just from a superficial standpoint, the two battles seem sort of analogous with a besieged and surrounded force being resupplied solely by air, though they obviously had different outcomes despite the North Vietnamese hoping to turn Khe Sanh into a repeat of their propaganda coup at Dien Bien Phu over a decade before. Why was that?