Dubious victory: Cillian Murphy as the title character in ‘Oppenheimer’.

OPPENHEIMER ****1/2 (180 minutes) MA
With Oppenheimer Christopher Nolan delivers what is arguably his best film yet and easily the best cinema release so far this year.

It’s certainly the most respectful to a mature, thinking audience, securing Nolan’s position as one of the few A-league directors dedicated to making big-screen films for grown ups. After Dunkirk, the Dark Knight films, Interstellar and Inception, chalk this up as another hands-down triumph.

Superbly directed, Oppenheimer is an engrossing historical drama from first frame to last, its three-hour running time lubricated by a sleek non-linear narrative that seamlessly shifts between three key timeframes in Oppenheimer’s life.

With Cillian Murphy excellent in the leading role, the absorbing biopic tells the story of J. Robert Oppenheimer, the ground-breaking physicist who was made director of the US military’s strictly secret wartime program to beat the Nazis and the Russians in creating a nuclear device.

As a young scientist with an somewhat unstable disposition we see him in academia as he establishes his reputation as a pioneer in quantum physics.

It’s here he meets Lewis Strauss (Robert Downey Jr.), a major figure in Oppenheimer’s life who would later become head of the Atomic Energy Commission where his early support for Oppenheimer morphed into something more insidious.

At the heart of the portrait, of course, is the detailing of Oppenheimer’s work at the scratch-built Los Alamos facility in New Mexico, where he and his brilliant, fiery team of international scientists raced the clock to design and test the world’s first nuclear bomb.

The third and most dramatically revealing phase, judiciously interspersed across the breadth of the film, gives a harrowing account of Oppenheimer’s post-war ordeal as he is hounded by Strauss and his minions as a threat to national security.

The motivation for this prosecution stems ostensibly from his early links to Communism, with his wife Katherine (Emily Blunt) having once been an active participant.

The real driver, though, is Oppenheimer’s advocacy for the containment of nuclear weapons, something Strauss, now a powerful conservative politician, is more than eager to shut down.

As historically important as the story is, Nolan wisely keeps the film itself from becoming self-important by pulling focus on Oppenheimer’s conflicted conscience, which becomes the narrative’s major through line.

Having succeeded in giving the military the weapon it needed to wreak upon an ever-defiant Japan and so bring the war to an end, Oppenheimer is beset by a guilt, even as he delivers a victorious speech to his cheering team.

American flags are waving everywhere as he merrily quips about how his only regret is not getting the chance to use the device against the Nazis. Yet the moment is undercut as his head fills with visions of blinding light and scorched skin.

This is one of the great moments in the film.

The case in favour of bombing Hiroshima and Nagasaki is made with great emphasis, the stress being on the millions of lives a mainland invasion would otherwise cost.

This is probably the most contentious part of the film, though Nolan’s clear intention is to highlight the horrific logic that strategic thinking must follow in the face of a failing adversary that refuses to yield.

Nonetheless the human toll of the bombings plays havoc on Oppenheimer’s conscience. Having developed the weapon to end the war, he hoped its awesome power would end all war only to become consumed by the fear of how his creation could end the world.

It’s a theme Nolan renders with great dramatic power, the post-Hiroshima speech scoring as a scene of piercing brilliance.

Cillian Murphy puts in an outstanding performance, playing Oppenheimer as a man of science who came to question his own humanity and whose integrity was turned against him.

As his chief counter, Robert Downey Jr is searing with his turn as Strauss, a complex character of shifting moral shades and fierce political instincts. After all the superhero shenanigans, it’s so good to be reminded of just how good a dramatic actor Downey can be.

Others in the sterling supporting ensemble include: Matt Damon as Oppenheimer’s likeable army boss General Leslie Groves; Emily Blunt and Florence Pugh (both putting in strong work in a film that is almost all-male); Rami Malek; Casey Affleck; Kenneth Branagh; Tom Conti (as Albert Einstein, the man who laid the foundation for nuclear science); Gary Oldman (in a ripper cameo as President Harry S Truman); and Josh Hartnett as a fellow physicist.

The cinematography is superlative. Shot entirely on film with IMAX cameras, Oppenheimer has a look that is both lush and intense, with Nolan’s use of black-and-white echoing Oliver Stone. One can only salute Nolan for continuing to champion the texture and vividness only achievable with film.

Along with the extraordinary images and visual effects, Oppenheimer also boasts a masterful sound design, delivering its biggest aural punch during the incredibly tense early-morning bomb test.

It’s a moment of pure cinema, deploying the type of ingenious, counter-intuitive touch that would make directors such as David Lean and Alfred Hitchcock stand up and applaud.

It’s no bold assertion that Oppenheimer has got Oscar written all over it. Nolan should be clearing out some shelf space for we’ll be blessed indeed if we see a film before Christmas that tops it.

FOOTNOTE: An added, though probably unintentional, bonus with the film is the detailed manner in which the process of reputation assassination is depicted. It serves as a sobering contrast to how such an attack would occur today.

Back then in the late 1940s, with Senator Joseph McCarthy’s hunt for communists in full flight, the quest to destroy a man involved a sham committee, a team of collaborators and a highly co-ordinated smear campaign running for an extended period.

Today such a mission would all be done in less than a day, launched by one person making an unfounded allegation online that would then go viral before the target had any reasonable chance to respond.