To title a movie "'71" is to be at once vivid and vague. It implies a measure of thematic interest far beyond the constraints of a typical film, without actually conveying much to its audience about what might be in store.

Yann Demange's picture follows British new recruit Gary Hook (Jack O'Connell) as he scrambles to get back to his base on the dangerous streets of Belfast in the early period of the troubles in 1971.

The film is a tense, introspective action movie, not the broad look at the geopolitical and on-the-ground realities of a critical year for a nation divided in brutal fashion that one might expect out of the sweeping title.

And that's fine. The movie works quite well, capturing the endless deceptions that endanger the protagonist as he searches in vain for someone to trust, while being hunted for execution by the IRA.

Demange is an accomplished stager of set pieces and he infuses the film with an unrelenting tension.

The movie explores every contour of these urban spaces, in which even homes and a seemingly friendly pub offer no safe harbor. Parallel action and long takes show us the advancing forces closing in on Gary and the steady desperation of his plight across the dangerous streets. The violence is sudden and matter-of-fact and the message is clear: There's no one to be trusted.

The film is an accomplished technical exercise molded out of sheer muscular filmmaking; it's intense and exciting, without actually amounting to much in a larger sense. Sometimes that's enough.