Disappointment occurs because Daschle did not beleive the terrorists would attack him. He had to believe that the terrorists saw Daschle as a friend.
Daschle was disappointed because he did not expect the Islamis terrorists to go after him. He expected them to see that he was not their enemy. It seems certain that Daschle does not see himself in the same class of Amercian as the people in the WTC or the Pentagon. For if Daschle saw himself as being the same as those atacked, he could not have been disappointed at being attacked.
Only if Daschle sees him self as of a different class than our busines and military leaders, could he be disappointed at being attacked.
It also means that Daschle did not see the terrorists as being really bad people. He saw some justification in their attack on the WTC and the Pentagon. He was disappointed because he could see no justification for the terrorists to attack him.