I was in Jordan (
) just before the outbreak of Gulf War 1. The Embassy was looking at evacuation of British Nationals then. The deal was that the UK would provide flights but they would be charged at a rate well above commercial rates. A lot of Expats were not happy at this at all. The line from the Embassy was to get out by commercial/own steam means (air and land) as soon as possible as it was probably a quicker, and cheaper, option.
The other problem was that a lot of Expats had not bothered to register with the Embassy when arriving. Therefore, the staff had no real idea how many people were actually there. I imagine the Embassy in Libya has been a scene of chaos. As to the FCO, it is staffed by terribly clever things from Oxbridge who have learnt everything they know about the world from a book, or Daddy's photo album. You know.......w@nkers.
Similar thing in Malaysia after 9/11. Lots of Expats getting jittery and were told to make their own way out. Not just the Brits but all Nationalities. (People were getting jittery because the local shops were selling 9/11 goods in most of the shops i.e bathrrom tiles showing the aircraft crashing into the Twin Towers: a best seller apparently
)
Diplomacy/Stiff Upper Lip and politics play as much a part in this as logistics,
especially when there is oil involved!!