http://www.reuters.com/article/2013/09/29/us-colombia-rebels-jackson-idUSBRE98S0HL20130929
"The FARC had requested on Saturday that Jackson assist with the freeing of Sutay. They say they are holding the former Marine as a prisoner of war and accuse him of being a mercenary.
"The FARC is considered a terrorist organization by the government of Colombia."
http://en.wikipedia.org/wiki/FARC
Does Jesse Jackson represent the U.S. Government? No, he's in Colombia as a private citizen trying to secure the release of an American veteran. Nuthin more, nutin less!
"The FARC had requested on Saturday that Jackson assist with the freeing of Sutay. They say they are holding the former Marine as a prisoner of war and accuse him of being a mercenary.
Jackson retorted on Sunday that the U.S. government supported his efforts and that he hoped the Colombian president "can evaluate the importance of retrieving an American veteran," adding that he still intended to go to Colombia in a matter of days to retrieve Sutay."
"The FARC is considered a terrorist organization by the government of Colombia."
http://en.wikipedia.org/wiki/FARC
"Jackson retorted on Sunday that the U.S. government supported his efforts"
I wouldn't call this a U.S. authorized diplomatic mission, but he did say the U.S. supported his efforts, as a private citizen.
He was there as a private citizen, and in your opinion that made him an idiot. Which I may or may not agree with. 
Why is Rodman an Idiot, and Jackson not?
http://www.theeroticreview.com/discussion_boards/viewmsg.asp?MessageID=205699&boardID=39&page=