This album started to build with War as U2 found a good clean clangy melodic sound that framed Bono's aggressive and emotional lyrics and singing. It developed further with The Unforgettable Fire as they started to bring more depth and polish to the music and as Bono's lyrics began to develop deeper meanings and more maturity. From those two albums came this. A perfect blend of all the things they had been working with before. The aggression and passion of War, but with a more mature voice, a much more mature sound that adds even more depth than The Unforgettable Fire but still manages to better expose the clangy unrelenting melodies that lie underneath. It is by far the strongest set of songs U2 ever brought to an album and the best vocal work Bono had done up to that point. The last two songs are the weakest point of the album, which hurts since it's better to close strong, but it is still a solid album.
As happens to any group that reaches this sort of climax U2 was left with no room to grow with this sound and would choose to reinvent their sound later, but this album still represents U2 at their best and is the reason they became superstars.