He strides across the stage like the warrior he is – supremely, inveterately confident. Forward motion is his creed; nothing can detain him long. He bears the mark of his years on the battlefield – a face and manner no longer youthful, a body made strong through exertion. His is a voice used to giving orders – gruff, hard-edged, unsentimental – even when he speaks to himself. When pushed beyond his limits, he roars.

Liev Schreiber makes a coolly charismatic Macbeth in the Public’s atmospheric but uneven new Shakespeare in the Park production, now at the Delacorte. Well-known for his cerebral force, Mr. Schreiber has no trouble pronouncing those tongue-tripping lines in his enviably rich baritone. Effortlessly, he navigates the hairpin turns of Macbeth’s speeches.

But his Macbeth is no intellectual. He shoves his guilt into a subconscious chamber. Hamlet may linger over his indecision, but Mr. Schreiber’s Macbeth has little patience for entertaining doubts. He hastens through his spoken misgivings, which seem to rise unbidden to his lips. He’s a man of action, and deep down, a fatalist.

Mr. Schreiber’s pale, blank face and largely unsentimental delivery give Macbeth a cool inaccessibility. In monologues and asides, he commands attention with his profound stillness, so that everything on stage falls away except the spot where he is standing. He draws us in by refusing access; we pine to get past that aloof exterior.

Mr. Schreiber’s chilly elusiveness works perfectly for “Macbeth,” a play whose success depends on the audience’s awed interest in its murderous protagonist. As he charges through the play’s three worlds – the supernatural witches’ world, the world of great men and deeds, and the domestic world – his combustible nature needs to collide with other flammables, thus goading him into action.

That chemistry works in the opening scene on the heath, as the three hair-raising witches taunt him. When he says “Stay, you imperfect speakers, tell me more,” it is almost possible to see him step into the spell. Macbeth may be a warrior and a statesman, but he’s also superstitious, susceptible to the same folk beliefs and primitive fears as the men he leads. These weird sisters (made vivid and creepy by garish makeup and spooky effects) insinuate themselves into the dark, irrational corners of Macbeth’s psyche.

Far less ominous is Jennifer Ehle’s unprepossessing Lady Macbeth. With her porcelain complexion and golden curls, Ms. Ehle looks uncannily like a young Meryl Streep. When she first appears, in a World War I-era bright pink gown, it’s hard to imagine that venom could be lurking beneath those rosy cheeks. (She couldn’t be further from Judi Dench’s iconic Lady Macbeth, she of the dark head scarf and shift.)

Playing against all that pink might have proven an interesting choice, but Ms. Ehle seems to have trouble building steam.Lady Macbeth is expected to work some angle on her husband – to seduce him, to ridicule him, to question his manhood. But there’s no clear intention here. Ms. Ehle’s performance gives no strong of Lady Macbeth’s conflicted interior life; just a sort of basic mercenary instinct. Without some sort of duality to work with, the sleepwalking scene – usually the piece de resistance – makes no sense.

Opposite Ms. Ehle, Mr. Schreiber finds himself in the awkward position of a man trying to start a fire with steel and no flint.The play’s intimate domestic world – which ought to be so full of frisson and danger – is flat in this “Macbeth.” Only when the world of men and deeds comes into the domestic world – at the ill-fated banquet – do husband and wife snap to life. As the drunk Macbeth leaps onto the table, knocking off glasses, dazed by visions of the ghost of Banquo (the dear friend he’s just had murdered), Lady Macbeth defends them both with uncharacteristic vigor.

Ultimately, it is the public world which emerges as the strongest of the three. Moises Kaufman (“I Am My Own Wife”), directing full-length Shakespeare for the first time, seems most at ease among the lords and kings; their scenes have a rising heroic thrust. Shakespeare, too, wants this world to grow steadily; from the moment that Macbeth’s men slaughter Macduff’s wife and son in cold blood, the world of men is decisively ripped in two; now there are men who stand for goodness and men who stand for greed.

Mr. Kaufman intercuts the murder of Macduff’s wife and child with Macduff’s audience with Malcolm, in a nice echo of the play’s obsession with the difference between words and deeds. As Macduff, Sterling K. Brown successfully builds a reverse Macbeth – a man whose love of country dwarfs his love of self, a man who will “blunt not” his stricken heart, in contrast to the increasingly numb Macbeth.

Yet even as he raises the value of the noble warriors, Mr. Kaufman has a double agenda. Both he and the Public’s director, Oskar Eustis, have spoken in interviews about what they perceive as the political importance of doing “Macbeth” during the Iraq war. With his roughly World War I costumes and music, Mr. Kaufman clearly wants to tie Macbeth to a more relatable era.When the final battle is launched, Mr. Kaufman pipes in dramatic choral music and has the soldiers gunned down in slow motion, one by one. In a tacked on epilogue, the witches prophesy the inevitable next cycle of war.

To hype the brutality of war feels almost nonsensical in this context. Shakespeare didn’t have a problem with Macbeth as a warrior, though he’s killed countless soldiers on the battlefield before the play opens. It’s the fact that Macbeth commits premeditated murders in cold blood that causes his moral decay. Even as Mr. Kaufman is preaching against the horrors of war, Shakespeare is sounding the trumpet to send 10,000 men charging back to take Scotland from Macbeth, and building anticipation for Macduff to fulfill the prophecy and slay Macbeth.

There are, nonetheless, many atmospheric marvels in Mr. Kaufman’s production. Derek McLane’s set – a gilted, cobalt-blue castle interior, with staircases and entranceways – combines the spare with the gloomy to brilliant effect. The set stands between the audience and the park beyond for almost the entire play, until the critical moment when Birnam Wood comes to Dunsinane.Then the doors are flung open, revealing the floodlit trees tossing in the night air. (For a brief instant,I thought the soldiers might advance swathed in branches, like a wood eerily come to life – but no.)

Mr.Kaufman sets a windswept nocturnal mood, but it is Mr. Schreiber who animates this “Macbeth,” finding the treasures buried in those familiar verses and speaking them plainly, so that both the newcomers and the devotees can recognize them.His command of the muscular language and complex psychology of Macbeth establishes him once again as one of the most compulsively watchable male leads onstage today.

Until July 9 (Central Park, at 81st Street, 212-539-8500).