After the Benghazi incident I kept hearing that there was no way to provide air support in a timely manner, so I looked for the closest U.S. airbase, which was in Sicily, a couple hour flight from Benghazi (less than 500 miles). I called the base there to ask why they didn't supply support, and the person said something on the order of, "You will have to bring that up with higher command". (I bet there were some very upset military people in the region who couldn't stand that they were ordered not to help!)