Fame
In light of recent events, this one is kind of touchy, unfortunately. Pretty much no one knew who John Christopher Stevens was before September 12, 2012, but he rapidly became a household name afterward. That was the day Americans learned that the U.S. had lost an ambassador for the first time since the Iranian Revolution in 1979. Stevens, our ambassador to Libya, as well as an information officer, and two former Navy SEALs acting as Stevens' security detail were killed in Benghazi when Islamic militants overran the U.S, compound.
Not exactly a feel good story, is it? But diplomats who don't hold the title Secretary of State generally don't usually become famous for happy reasons, we're sorry to say. While hopefully nothing like Benghazi will ever happen again, it typically takes something pretty bad for someone in the Foreign Service to gain notoriety.