Sicario is the result of a talented director bringing his typically dark vision to an already deadly serious script written by a TV actor- but it's better than that description might make it sound!
The director is Denis Villeneuve, a French filmmaker whose last two movies have been unapologetically bleak: his Prisoners was a violent tale about child kidnapping and his Enemy was a twisted story about doppelgängers stealing each other's wives (and some complicated metaphors about giant spiders, I didn't understand that movie at all). The screenwriter is Taylor Sheridan, an actor from Sons of Anarchy, and this is his first screenplay to become a feature film. The combination of Villeneuve's taste for the dismal and Sheridan's unseasoned authenticity is a worthy one: Sicario is a brutal and brutally honest thriller with a great cast and a uniquely blunt message- though it conveys this message inconsistently.
Speaking of blunt, Sicario's main heroine is portrayed by a very game Emily Blunt. She's been making a name for herself lately as a capable action star with movies like Looper and Edge of Tomorrow, and in this film she takes that role to a deeper level. Blunt plays a moralistic FBI agent assigned to help a covert team take down a Mexican drug lord. The script doesn't make too much fuss about Blunt fulfilling a "strong female lead" archetype- she simply is one (more movies nowadays should be normalizing such a role) and Sicario is better for it. Blunt impressively expresses both unyielding firmness in the face of adversity and brokenness amidst the movie's overwhelming hopelessness, and gives us a compelling reason to ponder the movie's message through her eyes.
Her antithesis throughout the movie is Benicio Del Toro's mysterious character, which Sicario prefers to tell you little about, so I will refrain from doing so as well. I can tell you that Del Toro perfectly exemplifies the film's main themes with chilling coldness, giving us an equally compelling reason to understand the movie's message through his eyes instead- though the audience may be more reluctant to do so. Josh Brolin is worth mentioning as well for turning his sarcasm up to 11 and giving an otherwise humorless movie a comic relief character.
Sicario's message is certainly the film's defining feature. Villeneuve's movies are typified by an unflinching dedication to dark subject matter and digging deep into human depravity- so he's the perfect person to bring Sheridan's screenplay to life. Sicario proceeds through many usual cinematic checkpoints of a movie about illicit drug trade: brutal cartel murders, putting together a covert operation, tortures and questionings, the hunt for the drug lord, etc. What elevates this movie above a typical procedural is its resolute depiction of a moral code having absolutely no place whatsoever on both sides of the narrative equation.
Do the Mexican drug cartels have any kind of ethical code? Perhaps not- but does the American team chasing them down have one? They should... right? Sicario explores these questions right down to their disgusting cores without reservation, and then successfully juxtaposes the human darkness that it uncovers with Blunt's impassioned calls for principles amongst the mess. As the movie's events drown out her cries in depressing reality, her character becomes more and more diminished in a narrative sense- and the audience becomes more and more discouraged. This is intentional, and it's a powerful look at an unfortunate truth.
It's a look that's not taken enough, however. Sicario is thematically deep, but its biggest drawback is a noticeable lack of thematic consistency. There are a number of narrative mysteries that the movie answers near the finale, but while it hides these from the audience, it does not develop its message at all. The beginning introduces the movie's themes, the finale expounds upon them dramatically, but the midsection becomes a sagging transition between the two. Yes, it matters to the story, but the story is uninteresting when separated from its dark themes. There's a bright spot involving The Walking Dead's Jon Bernthal, but after this it quickly sinks back into tiresome territory until the last half hour.
The thing's superbly shot though. Roger Deakins- probably the best living cinematographer- is responsible for Sicario's photography. Every shot is meaningful and stunning. If Deakins doesn't finally get his well-deserved Oscar for this movie, the Academy truly is inconsequential.
If you're willing to get through Sicario's lackluster middle, the first and last sections of the film are tension-filled masterpieces of filmmaking. I personally think they're great enough to give the entire movie a solid recommendation- just don't blame me if it makes you lose faith in humanity.