That call was not simply a call to the annex. It was a Critical Incident Report that automatically triggered the alarm in Tripoli, D.C., Eurocom, Africom and every CentCom sit-room in the world. In D.C. that includes the WH sit-room, Pentagon sit-rooms, CIA sit-rooms and the State Dept. sit-room. Probabaly the NSA as well. All of those sit-rooms were already on high alert due to several other embassies having been under assault earlier in the day. FWIW that would have been 3:40 PM in D.C.
Whats the old cavalry command ? Ride to the sound of the guns?