Just not for Chris Stevens and not last September:
When then-Secretary of State Hillary Clinton made an unannounced part-of-the-day visit to Tripoli, Libya, on Oct. 18, 2011, the U.S. Defense Department pre-positioned assets off the Libyan coast in case it needed to rescue the secretary of state.
The fact that the assets were pre-positioned for Clinton’s visit was included in the annual report of the State Department’s Bureau of Diplomatic Security (BDS).
Here’s part of the page from that report (PDF):
Before her visit to Tripoli in 2011, when they asked Hillary if she wanted extra military protection just in case, do you think she answered “what difference does it make?”