I just saw this film at the San Francisco International Film Festival (in Berkeley) Without a lot of self-righteousness or bloviation, this film is superb. It takes a subject which may not lend itself well to film and makes it immediate and visual. The use of animation and music is masterful. The interlocutors (lighted beautifully) make you hang on to every word they say.
It has a point, but it allows other viewpoints in, and not just straw men. The filmmakers give credible, reasonable arguments for taking a position which is ostensibly alternative to theirs. It actually stays away from, for the most part, the easy, well worn targets and examines in a fresh way, the impact of secrecy. Interestingly, at no point do they ever suggest giving up security--Actually they seem to be very much in favor of it.
Interestingly, Dan Ellsberg (Pentagon Papers) was in the audience when I saw this movie. I'm surprised he would be drawn to it, having lived it firsthand but it shows the quality of the work.
A masterpiece.