And both of the well-known live versions are really good, much better than the original album version. In fact, it can be plausibly argued that the live releases of this song were the underlying reason why they went from top-echelon stars to the biggest on the planet when "Joshua Tree" came out in 1987; because they were MTV stars already because of the live performances. Bad is, like Wire, full of angst and frustration at the inability of a loved one to do anything to help an addict that does not want to be helped. And the "roll call" of emotions is devastatingly effective--"isolation, desolation, temptation, separation", all the rest, are something both addict and their loved ones can identify strongly with. To this day, I'm not sure if the song is from the point of view of the friend, or if it is a dialogue; you can make a case for either.
But in any event, it remains, 30 years later, a powerful song. I am going to include both live versions that I referred to, without putting the album version up; it's pretty lame compared to these two.