Garance Franke-Ruta at Tapped says her sources at the State Department suggest that the U.S. hasn't rushed to evacuate Americans from Lebanon because it would  a.) create the impression that American citizens are being threatened by the actions of a longtime U.S. ally, and b.) contradict our stated support for the Israeli assault and willingness to wait and let it continue.  This explanation is most likely, but its hard not to notice that a lot of other countries haven't had that dilemma, and the fact most have pulled their people out of the country very quickly suggests the situation is quite dangerous and uncertain.  It is my hope we don't see any American citizens accidentally killed for the sake of avoiding some potential public relations problem.