Directed by Clint Eastwood. In Japanese with English subtitles. Rated 14A. Starring Ken Watanabe and Kazunari Ninomiya. Opens Friday, January 12, at the Fifth Avenue Cinemas

If war has any value in our existence, it is as a clarifier of human extremes. Whatever people are in “real” life, they only become more so under battle conditions. True or not, that’s the animating principle of Letters From Iwo Jima, Clint Eastwood’s foreign-language companion piece to his Flags of Our Fathers from last fall.

This time, old flint eyes gives us this pivotal late conflict in the Pacific War from the Japanese point of view. Working from a script by Iris Yamashita, based on the story she developed with Flags writer Paul Haggis (and using a collection of real letters), the veteran director focuses on a few key players in the violent drama that took place on Iwo Jima. Literally chief among these is General Tadamichi Kuribayashi (Memoirs of a Geisha’s Ken Watanabe), sent to command the island’s defence after the bulk of the Japanese fleet was wiped out near Midway Island.

A western-educated fellow with flexible notions of warfare and life, he shocks his fellow officers by abandoning what he sees as a hopeless attempt to forestall a massive Allied landing on the beaches (to still-debatable purpose) and retreating to hillside tunnels, just as he is shocked by their ignorance of how the war is really going. Also on hand is the glamorous Baron Nishi (Tsuyoshi Ihara), a former Olympic champion who has brought along his favourite horse upon which to do chivalrous battle.

At the bottom of the pecking order is Saigo (Nippon pop star Kazunari Ninomiya), a young draftee who has recently had to abandon his pregnant wife at their family bakery, which, in any case—as we see in stark flashbacks—had already been stripped bare by local opportunists seeking to punish anyone not displaying proper patriotism. Saigo is regularly beaten by superiors who find him insufficiently fanatical. And some, like the glassy-eyed Lieut. Ito (Shido Nakamura, last seen in Jet Li’s Fearless), prove to be singularly unresourceful once the fighting starts.

Saigo keeps crossing paths with the improvisational Kuribayashi, affording us a high-low view of soldierly reactions to steadily worsening conditions. The film’s most harrowing sequence, for example, finds a whole squadron of men ordered by robotic middle management to commit suicide by hand grenade—in direct contravention of the general’s orders to keep moving and fighting.

Eastwood does a masterful job of individuating the men we meet, and only during rare encounters with single Americans—as when the Baron rescues a wounded GI—does the script approach maudlin message-making. For every small misstep, though, there are a dozen moments of subtle brilliance, such as the brief glimpse of Yanks raising a flag on distant Mount Suribachi—an iconic image to us, but insignificant to soldiers fleeing for their lives. The movie itself, gradually drained of colour over the course of two hours, delivers a resounding slap to received wisdom about war—including the trope that it makes men out of boys. Mostly, it just turns them into meat.