Ed Zwick has truly become the Stanley Kramer of our time, a man who uses his films to tackle Big Issues in a fundamentally pedestrian way. It’s hardly surprising, therefore, that, like Kramer (“Judgment at Nuremberg”), he’s gotten around to the Holocaust with “Defiance.” Baldly calling itself “a true story” rather than using the more euphemistic formulation “based on a true story,” the picture focuses on three Jewish brothers who organize the survivors of massacres that occur in Belorussia after the German invasion of 1941 into a forest community, which they then use as a base for resistance activities in collaboration with Soviet partisans. It’s a potentially inspiring episode treated by Zwick and co-writer Clayton Frohman in such a formulaic fashion that it becomes a sort of Spartacus on the Steppes.

The Bielski brothers flee into the forest after their family is killed by bigoted local cops in league with the Nazis, and other stragglers are drawn to them almost by fate. Forming an impromptu settlement, they necessarily venture out of the woods to steal or cadge supplies from the locals and deal with collaborators and German patrols, eventually coming to the attention of the partisans led by a Soviet officer named Panchenko (Ravil Isyanov) and his bigoted thug of an aide, Gramov (Rolandas Boravskis). Tuvia (Daniel Craig) is an erstwhile smuggler, but proves the strong, responsible sibling, who (after one bloody act of vengeance, against the policemen who killed his parents) becomes the leader of the ad hoc forest band, believing that the best revenge is to survive. While he declines to abandon the settlement, the more volatile, hot-tempered Zus (Liev Schreiber), who has always had a turbulent relationship with the previously ne’er-do-well Tuvia, leaves the group to join the Russkis after learning that his wife has been killed in the aftermath of the invasion. Meanwhile young Asael (Jamie Bell) grows into a man during the war, even taking on a wife (Mia Wasikowska) while serving as Tuvia’s loyal aide. (A fourth sibling, Aron—played by Georghe Mackay—is but a boy, and virtually disappears in the latter stages of the picture.)

Precisely the sorts of episodes you’d expect form the bulk of the narrative. There’s a romance between Tuvia and a lovely woman named Lilka (Alexa Davalos). Shortages of food lead to hunger and arguments. Tuvia falls ill and has his leadership challenged by one of the men (Sam Spruell) who claims for himself and his hunters preference at meals. Zus becomes one of the partisans’ fiercest fighters but still finds himself the target of anti-Semitism, and when he learns of the illness in the refugee camp, he leads a dangerous raid on a police station to secure the necessary medicine his Soviet comrades will not part with. Supporting figures like Tuvia’s old schoomaster (Allan Corduner) and radical intellectual Isaac Malbin (Mark Feuerstein) are introduced to provide a note of levity (as well as contrast to the Bielskis’ rugged rustic competence).

Of course, a big finish is needed, and that’s provided when the entire forest group must evacuate their settlement in the face of a massed German assault. It’s the opportunity not only for supreme acts of self-sacrifice but a dangerous trek through swampland as well as a final showdown with the Nazis that—of course—involves a last-minute intervention that’s meant to come as a surprise but seems depressingly predictable.

Many, perhaps even all, of the events depicted in “Defiance” may actually have happened, but as portrayed here they seem the stuff of stilted docudrama rather than historical reality. That’s a pity, since the Bielskis’ story is (as the summations of their later lives shown during the closing credits suggest) a fascinating one, and the contributions of the technical crew—the production design of Dan Weil, the art direction of Daran Fulham, and particularly the cinematography by Eduardo Serra, with its moody color palette—are excellent.

The cast is a promising one as well. Craig, with his piercing gaze and stalwart good looks, is a natural as Tuvia, and Schreiber has the gruff personality and strong physique that Zus requires. But they’re both hamstrung by the director’s unsubtle, unvarying approach and a script that allows them too little shading. Bell actually comes through best, since the script is better at balancing Asael’s gentleness and courage. The supporting characters, unfortunately, are drawn with even less skill, making them all virtually one-note figures.

One wishes that the Bielskis’ story could have defied Zwick’s penchant for self-important mediocrity and moved him to something beyond the usual level of his filmmaking. But unhappily it hasn’t. “Defiance” is a powerful tale, but one that’s done in so old-fashioned, heavy-handed a fashion that it already seems dated.