There are certain assumptions that American audiences, perhaps without realizing it, are likely to bring to a movie about World War II. The combat picture has been a Hollywood staple for so long — since before the actual combat was over — that it can sometimes seem as if every possible story has already been told. Or else as if each individual story, from G.I. Joe to Private Ryan, is at bottom a variation on familiar themes: victory against the odds, brotherhood under fire, sacrifice for a noble cause.

But of course there are other, contrasting stories, a handful of which form the core of “Letters From Iwo Jima,” Clint Eastwood’s harrowing, contemplative new movie and the companion to his “Flags of Our Fathers,” which was released this fall. That film, partly about the famous photograph of American servicemen raising the flag on the barren volcanic island of Iwo Jima, complicated the standard Hollywood combat narrative in ways both subtle and overt. It exposed the heavy sediment of individual grief, cynicism and frustration beneath the collective high sentiments of glory and heroism but without entirely debunking the value or necessity of those sentiments.

“Letters,” which observes the lives and deaths of Japanese soldiers in the battle for Iwo Jima, similarly adheres to some of the conventions of the genre even as it quietly dismantles them. It is, unapologetically and even humbly, true to the durable tenets of the war-movie tradition, but it is also utterly original, even radical in its methods and insights.

In December 2004, with “Million Dollar Baby,” Mr. Eastwood almost nonchalantly took a tried and true template — the boxing picture — and struck from it the best American movie of the year. To my amazement, though hardly to my surprise, he has done it again; “Letters From Iwo Jima” might just be the best Japanese movie of the year as well....