Widely misunderstood.
The lyrics were written by Bono during the recording of rattle and hum... A few years before the edge's divorce. It's fairly clear that the song is about terrorism, with some layers about love and relationships mixed in... making it seem to have multiple meanings, which adds to it's greatness (much like until the end of the world).
The part that is related to edge's divorce is the guitar solo... which he recorded while going through his divorce and apparently was much more violent in his recording than usual
