Sentence:  Actually , the officers on the ground had no intention of <WSD>letting</WSD> the hijackers get away with any kind of an airplane ; they had orders to that effect straight from President Kennedy , who thought at first , as did most others , that it was four followers of Cuba 's Fidel Castro who had taken over the 707 . 
Meaning of the word marked with <WSD> tags:  make it possible through a specific action or lack of action for something to happen