This film got stupid from the moment....
...When they realized that killing the "hosts of the ghosts" resulted in the ghost finding a new host... And yet they continued to kill them... LAME.
And as others have posited on the boards, going back to nuke them was a whole new level of special... What is wrong with the writers? It's like they intentionally took an okay idea and made it bad and wrong, with all the lead characters making illogical decisions constantly. Whatever you may think of Carpenter's previous creations, this was just plain lazy story telling, through and through.