Sigonella NAS in Sicily was on stand-by.
Sigonella is only 470 miles from the compound in Benghazi...and they were on stand-by with jets and C-130's. Even the C-130 could have made the trip in a little over an hour. An F-18 could have made a visit in under a half an hour.
Just a show of force--a sonic boom--would have given our men an edge
I can’t find my link to it now but early on there was an article about a special team from Germany that was moved to Sigonella ready and raring to go. As Travis McGee posted, they have teams who practice regularly for hostage/embassy rescue missions and they’ve been doing that for decades.