premise: But we know that at 10:31 , General Larry Arnold instructed his staff to broadcast the following over a NORAD instant messaging 10:31 Vice president has cleared to us to intercept tracks of interest and shoot them down if they do not respond per [ General Arnold ] .
hypothesis: General Larry Arnold told his staff to broadcast ovre a NORAD messaging service at 10:31 that the Vice president had said to hold off on shooting down any hijacked planes until the President could be reached .