The use of the "Lebanon" metaphor is very troubling. Many people suspect that all the tough talk, all the "We must win in Iraq", all the promises to not cut and run, that if Kerry is elected he will immediately claim that the war in Iraq is un-winnable and withdraw all our troops. The phrase "another Lebanon" references Ronald Reagan's failed effort to help in Lebanon and his decision to pull out all our troops after hundreds of Marines were killed when their barracks wer bombed. Kerry could have chosen many metaphors to describe chaos and civil war he chose the one in which even Ronald Reagan thought was so chaotic the only correct course was to withdraw our troops.
You've got that right.
The reporters seem to have picked up on it though, as every article I have read so far makes certain to mention what this reference to Lebanon means.