Actually, Logan didnt authorise the assassination of Palmer. In the recording between Logan and Henderson, Logan says that 'it wasnt part of the plan'. And the terrorist attack wasnt made 'possible', it was directed by Logan. Well, sort of, his original plan was to let the terrorists take the nerve gas to the Middle East, then release it inside the terrorist base. His next move was to then use that as a pretext to invade the Middle East and take their oil.

Hmm, sounds familiar...