I seem to remember in Algeria there was a bloody conflict or revolt against the French (words like terrorism keep popping up when I look it up online) in the Casbah area (old towns of Algeria) for about 6 years in the 1950s/1960s... I tried looking it up on the internet, and I didn't give much to show you.
My information on this is very bad, but I seem to remember that much... don't know if Bono intended this to be the meaning, seeing as how the song isn't really about this...