Unfortunately, the trailer was considerably better than the movie (watch it below).
The particular failings are too numerous and would be a waste of time to expound here. But the key flaw in The Good Shepherd was that there were really three plots going on simultaneously, .i.e., the history of the CIA, the story of Edward Wilson - both retrospectives - all the while pieces of a current plot were unraveling.
I understand the idea was to show different perspectives of the CIA at different times in its evolution and tie them together with Edward Wilson. However De Niro did not achieve this effectively.
The plots instead of supporting each other and flowing together to create a multi-dimensional tale, clashed with one another, fragmenting and ultimately canceling out the most interesting and potent aspects of the movie. It lacked a much needed constant from which the meandering events could resolve themselves into an intelligent whole.
If De Niro tried to tackle just the history of the CIA, or just the life of Edward Wilson, or just a cutting-edge spy tale - something more valuable may have come from the Good Shepherd project. But De Niro was overambitious. He overextended the limits of the story. He overextended the normal human tolerance for a lengthy non-sequential motion picture (it was about 3 hours long).
If you haven't seen this movie don't look at the following quotes. They are better heard than read.
These were my favorite lines in the movie.
Richard Hayes: I remember a senator once asked me. When we talk about "CIA" why we never use the word "the" in front of it. And I asked him, do you put the word "the" in front of "God"?
Joseph Palmi: Let me ask you something... we Italians, we got our families, and we got the church; the Irish, they have the homeland, Jews their tradition; even the niggers, they got their music. What about you people, Mr. Wilson, what do you have?
Edward Wilson: The United States of America. The rest of you are just visiting.