I thought Babel was very good, but I had several problems with it. The non-linear narrative, for one, wasn't as essential to its meaning as in 21 Grams, it was more of a gimmick, less exciting, and in the end probably overlong. A few of the different narrative strands connected in a very wishy-washy way, and the Mexican boarder scene surprised me in how typical and ordinary it was. I had expected more of the director.
I presume you mean parallel stories, rather than non-linear. I thought that each of the stories was linear by itself. My friends had problem with this and several other points. We went to the theater thinking that this is a story about an American couple in Iraq (it turned out to be Morocco!). We had no idea that there were 3 parallel stories. So all of us were waiting for the connection between the other two stories with the Moroccan one, which we thought was the main story. Half way through I realized it and watched the rest of the movie without that bias. Secondly they were looking for a strong connection between the 3 stories, which essentially was not the intention of the director. The connection, whatever little was just accidental, it is a trivial part in the big picture. The Morocco Story - 2 arcs. A peaceful family dragged into problems and death because of the inherently sly nature of the younger son. A tragedy. A couple with marital problems discovering their love when faced with adversity and fear of death. A positive arc.
The Japan Story - A complex arc It starts happily with a deaf-mute girl with her friends, then descends deeper and deeper into tragedy with her sexual frustration. But at the end of it all she regains the love of her father who till then had been a stranger to her practically. The Mexico Story - Completely tragic arc. What should have been a routine day ends up totally life altering for the kids and the nanny, who after 15 years finds she cannot enter US. The kids are totally scarred with the near death experience.
That is how life is, bizarre. Unexpected tragedies and reversal of fortunes. I liked how the director deals with this theme with comparisons and contrast. My favorite is the Japan story however. It is beautiful, tragic, but ultimately reassuring. Great effort thematically. Ofcourse the technical brilliance has been alluded to by others including yourself. I would also like to mention that the very wide-angle closeups in Morocco were good.
