Well as I understand the situation unfolded at the time, the Benghazi 'compound' had two parts. One, the physical consulate, and a short distance away a CIA compound,called The Annex.
The CIA team worked to fight its way to the 'consulate' and rescue the ambassador and his staff, and were unsuccessful. That CIA team says they were told to stand down by the most senior on site CIA team member, and that he did so on his own authority. This individual only ever referred to as 'Bob' spent 20 minutes on his cell trying to get a rescue op sanctioned, but apparently never did. It resulted in a 30 minute delay before the CIA team entered the fight. They say they also asked for close air support, and none was ever provided.
The team went of its own volition and saved 20 American lives.
The more confusing 'order' was in Tripoli. You had 4 security team members who wanted to go to Benghazi but were told to 'stay in place' to protect Tripoli staff who had actually bugged out of the embassy there. They had also destroyed classified materials and computers, and were at a 'safe house' location. The team stayed with diplomatic staff, and eventually wound up treating the Benghazi injured who were later evacuated.
Rear Adm. Brian Losey who was the African Theatre Spec Ops commander is the one who issued the 'stay in place' order. Stand down by any other name as it were. His opinion is they wouldn't have made a difference, and they had other duties.
Of note is if he makes the call himself or if the White House or State provided 'input'. No one has ever actually answered THAT question.
NOW STUDENTS (lol) here's the REAL issue you need to find the answers to. The U.S. compound was a CONSULATE, NOT AN EMBASSY. Why does that matter? Consulates are where you go for help to replace a lost passport, find a local doctor or lawyer if you've broken a local law, had a birth or death on your trip, or been a victim of crime.
EMBASSIES are created to the tune of exactly ONE per country, AND in the capital city of that country. CONSULATES can be several in number throughout a large country based on need.
So WHY did the U.S. have a facility in the middle of a civil war zone that primarily is supposed to assist tourists, and is being guarded by 'contractors' and in close proximity to a CIA facility? Oh and what were Christians In Action doing there as well?
Find the answers to those questions and you may be able to posit a theory as to why seemingly no one made much of an effort beyond the local CIA guys to save anyone during this attack.
Fast and Furious on Steroids!