Hmmm.... I don't know about the romantic picture in general, is it just our dim look back in time?
I also wonder is it possibly that, thirty years ago, the violence and oppression was localized to those areas and cultures, and the rest of the West didn't care that much? Or that things really were better (reading the experiences of Norman Schwarzkopf growing up in Iran, or seeing pictures of the medical school students in Afghanistan in the 60s, does make me think that much of that culture has changed).
Probably at least some people knew what "...to the shores of Tripoli" meant in the Marine Hymn.
And back further, I think many people knew of the story of the Commerce: http://www.amazon.com/Skeletons-Zahara-True-Story-Survival/dp/0316159352