The title, Cicario (2015), is cartel slang for “assassin” or “hitman”, evidently derived from the first-century Sicarii zealots of Judea, though the word is never spoken out loud in the script; screenwriter Taylor Sheridan defers the revelation of how it really applies here to the end of drama, and this disclosure ties up its attendant issues of justice versus revenge, idealism versus cynicism and how American justice is to be applied beyond US borders without anything as quaint as a formal declaration of war. The idea that the war on drugs might be won is not something anyone takes seriously. The only question is how the forces are aligned and who is enforcing the rules of engagement.

The action is viewed mostly through the eyes of Kate Macer (Emily Blunt), an F.B.I. agent. Blunt is impressively glum and intense, but Kate is a bit of a blank, on hand as a filter through which the audience can scrutinize Matt and Alejandro, who are far more intriguing characters.

The tenor and texture of the movie are established with that truly horrible scene at the very beginning where the FBI storm a cartel haven. It has its own sheen of horror, aided by the groaning orchestral chords in the musical score from composer Jóhann Jóhannson. The scene lays down a marker for the film’s status as something like a forensic thriller and in its way a procedural thriller, in which the covert procedure itself is the crime.

This is a real white-knuckle thriller, with screeching feedback notes of fear and paranoia, which plays out in a very satisfying atmosphere of pure nihilist ruthlessness. The movie asserts that the war on drugs has turned America into the very monster that they were trying to defeat.