Bush uses bin Laden to personalize the war.

He uses it like a mandala for all his minions and supporters to focus their hate, racism, xenophobia and fear upon. Mr. Bad Guy.

Bin Laden had to come back because if he stays silent and he is not located, the dems can use that as ammo in November that Bush's war is failing on every level. He PROMISED to find bin Laden, he PROMISED to find wmd. His failure to make good on one makes it necessary for him to make good on the other--until the election is over and Mr. Bad Guy slips away again--drat!

His personalizing of the war on terror doesn't work well for him publicly except at election time when it can be used to manipulate the fear vote. That's why the administration decided to go the personalization route. It already got Dubby a 2nd term so it has worked well. But by '08, this war had better be in hand and bin Laden had better be caught in a very public show.