For years, we thought Clint Eastwood was a taciturn man of action—until it turned out there was a sensitive ponytail tucked up under the Man With No Name’s sombrero.

Oh, he had us fooled good, what with the spaghetti Westerns and punk-taunting Dirty Harry-isms. But once he got behind the camera, he started deconstructing vigilante justice (Unforgiven), embracing his romantic side (The Bridges of Madison County), questioning jingoistic propaganda (Flags of Our Fathers) and even *gasp* pondering the ethics of euthanasia (Million Dollar Baby). And hoo boy, has it been something watching conservatives work themselves into a lather at seeing the iconic tough-guy go all soft and liberal on them.

It would be easy to see Letters from Iwo Jima creating yet another furor on the right side of the political spectrum. After all, it has the nerve to put a human face on all those Japanese soldiers that we were bent on killing back in Dubya Dubya Two, and a whole bunch of surviving Greatest Generation-ers probably aren’t ready for that kind of relativism. But in its sneaky way, Letters from Iwo Jima might actually be a Bill O’Reilly wet dream—because it’s hard to imagine a more effective attack on the horrors of suicidal anti-American nationalism.

It’s also not a half-bad little war movie. The principal narrative begins with Japanese troops in 1944 preparing for the anticipated American assault on Iwo Jima. Limited supplies and a wave of dysentery striking the soldiers make the prospects for holding the island bleak when new commanding officer Gen. Kuribayashi (Ken Watanabe) arrives, but he brings some unique tactical ideas inspired by his years studying in America. While this new style inspires loyalty in grunts like Saigo (Kazunari Ninomiya), it’s not nearly so popular with commanders like Lt. Ito (Shido Nakamura), who’s reluctant to abandon traditional ways.

On the surface, Letters from Iwo Jima is almost a too-obvious attempt at we’re-all-the-same-under-the-skin revisionist history. The film’s title comes from the notes home that are narrated throughout (in Japanese with English subtitles), dealing with such universal matters as missing loved ones and trying to do the right thing. When the Japanese manage to capture a wounded American at one point, and read a letter he has written to his mother, the similarities between the two cultures’ deepest concerns is obvious. Only apparently they’re not obvious enough, since one Japanese soldier—Private Thematic Exposition, I believe his name was—underlines the point by saying something like, “His letter is just like a letter I would have written to my own mother.”

Fortunately, Eastwood and screenwriter Iris Yamashita have more to say, and less pedantic ways in which to say it. Once the battle commences, Letters from Iwo Jima mostly becomes a study in the clash between two ideologies: the progressive, western-influenced sensibilities of Kuribayashi, and the old-world ethic represented by Ito. It also manifests itself in the character of Shimizu (Ryo Kase), a former member of the Japanese secret police whose own challenges to accepted practices haunt him. The film’s most harrowing sequences convey the depressing reality that the moderates haven’t got a prayer of persuading the fanatics to change their ways—not when notions of personal honor and sacred homeland tend to overwhelm reason.

Eastwood develops these ideas by employing the kind of restrained filmmaking that has characterized his best work as a director. One of his finest images captures the Japanese soldiers spotting the Americans raising the famous flag—at a great distance, scarcely long enough for it to sink in that we’re seeing an event about which Eastwood just made another entire film. The performances are uniformly terrific, led by the gifted Watanabe but nearly matched by Ninomiya as the survival-driven Saigo. They lead us through a story that’s less about pyrotechnics than it is about a plodding sense of almost certain doom, painted in chilly blues and grays.

Letters from Iwo Jima isn’t nearly as focused as it could be, employing frequent flashbacks that are at times illustrative, and at other times redundant. But it’s far more consistently compelling than Flags of Our Fathers, and far less wishy-washy than one might suspect about who the good guys and bad guys in this scenario really are. The surprise is that, just as it often happens in our world, we can find ourselves fighting against both of them.

LETTERS FROM IWO JIMA

*** (three out of four stars)

Starring: Ken Watanabe, Kazunari Ninomiya, Ryo Kase.

Directed by Clint Eastwood.

Rated R.