Let us recall today the Casey/CIA-organized car bomb assassination attempt against Grand Ayatollah Mohammad Hussein Fadlallah in Lebanon, in March of 1985. It killed 80 and wounded nearly 200 innocent civilians. Exactly the sort of thing that most people mean by terrorism.
80 people murdered under the auspices of the U.S. government, and no (public?) investigation.
According to Bob Woodward in his book The Veil, this was outsourced through the offices of then Saudi ambassador to the U.S., Prince Bandar bin Sultan, and contracted through the then head of Saudi intelligence, (and now Saudi ambassador to the U.S.) Prince Turki bin Faisal al Saud.
Under the doctrine that those who harbor terrorists are just as guilty as the terrorists, it follows that both the U.S. and the Saudis are guilty for harboring Prince Turki, and that the U.S. is guilty of terrorism for continuing to "harbor" the C.I.A.