LFF 2016: Snowden / The Birth of a Nation / Arrival

As an old Sixties lefty brought up on thrillers like The Parallax View, Oliver Stone loves ripping open great American political conspiracies, and inevitably he portrays CIA whistleblower Edward Snowden as a noble crusader for free speech and democratic accountability against the might of America's intelligence agencies.

If you work for the CIA you'll hate Snowden (★★★★), but Stone has fashioned the story into a tense, fast-moving drama which will leave you pondering over what's really justifiable for the greater good.

Joseph Gordon-Levitt's Snowden starts out as a sincere young patriot, training for Special Forces but rejected as not physically strong enough to make the cut. A computer genius, he joins the CIA instead and whizzes through the admission tests with astounding ease. However, as he's given various postings around the world, he becomes disillusioned at how the CIA and National Security Agency are abusing their seemingly unlimited powers, and is horrified by the way a programme he supposedly created, EpicShelter, is being used for marking targets for extermination in drone attacks. The sheer extent of what the Americans were, or are, up to remains flabbergasting. "You didn't tell me we were running a dragnet on the whole world," he protests to his boss Corbin O'Brian (Rhys Ifans), who likes to point out that "the front line is everywhere".

'The Birth of a Nation' could hardly be more timely

Stone isn't known for his light romantic touch, but he handles Snowden's complicated relationship with girlfriend Lindsay Mills (Shailene Woodley) deftly, and the way that Agency suspicions about Snowden's attitude to his work start to cast paranoid shadows over the couple's private life effectively personalises the broader picture. Indeed, the degree of intrusion which intelligence operatives are subjected to by their employers is a fascinating aspect of the tale. Scenes of Snowden hiding out in Hong Kong while Guardian journalists prepare to publish his reams of top-secret revelations tend towards melodrama, while Melissa Leo's portrayal of Laura Poitras (who made the Snowden documentary Citizenfour) is marred by the malevolent creepiness Leo brings to every role. Overall though, it's a much better film than Stone's recent history might have led you to suspect.

Arriving in an America outraged by police violence against black people and the rise of Black Lives Matter, Nate Parker's powerful diatribe against slavery, The Birth of a Nation (★★★★) could hardly be more timely. A dramatisation of the real-life slave rebellion led by Nat Turner in Southampton County, Virginia in 1831, it depicts Turner as a visionary preacher pre-ordained to lead his people from their bondage, though his bloody attempt to do so was doomed to failure.

Parker directed, stars and wrote the screenplay (the story is credited to Parker and Jean McGianni Celestin), and has brought a charismatic energy to the project which often overrides the orthodox nature of the storytelling. Taught to read as a boy by plantation-mistress Elizabeth Turner (Penelope Ann Miller), Turner studies the Bible, finds he has a gift for sermonising, and preaches the Word to his fellow-slaves. Times are hard, and at the urging of the Reverend Zalthall (Mark Boone Junior), Nat's owner Sam Turner (Armie Hammer) hires Nat out to local plantations, with the aim of placating rebellious urges among the slaves  with soothing Scriptural messages (pictured above, Armie Hammer and Nate Parker).

However, Nat's early optimism is soured by the appalling sights he sees on his travels (not least a scene where a slave has his teeth knocked out with a chisel before being force-fed). His preaching begins to sound more like an exhortation to fling off the chains of bondage. A couple of incidents of rape, including an assault by slave-catchers on his wife Cherry (Aja Naomi King), prompt Nat to recall that the Lord could be vengeful as well as merciful.

The slaves' retribution is merciless, as is the suppression of their revolt by the military. Parker has been accused of excessive self-regard for the Christ-like overtones in his portrayal of Turner, and more troublingly, the fact that both Parker and Celestin faced rape allegations in 1999 has provoked a political backlash in the US. But if we can judge the art and not the artist, this is vivid and unsettling film-making.

Although the appearance of a dozen alien spacecraft hovering at locations around the globe may prompt flashbacks to the earth-in-peril epic Independence Day, Denis Villeneuve's Arrival (★★★) is more philosophical and intellectual than a shoot-'em-up blockbuster. At the heart of the story is Amy Adams's Dr Louise Banks, a university linguist, who receives a sudden visit from the insistent Colonel Webber (Forest Whitaker). He wants her to translate whatever it is the aliens use as language.

It's the beginning of Banks's largely interiorised journey towards understanding the interstellar incursion, and she's startled to discover that the answers lie within her own mind. She's still grieving after the death of her daughter Hannah, and as she struggles to find a way to communicate with the visiting octopus-like "heptopods" she realises that the way her daughter learned language and visualising skills is somehow important. She needs to hurry though, because translation confusion is about to provoke global war.

Eric Heisserer's screenplay was derived from Ted Chiang's Story of Your Life, which proposes the idea that language can shape how we interpret the world. Thus, as she learns heptopod-speak (quaintly expressed by circular squirts of squid-ink) Dr Adams begins to grasp the notion of time as a continuum of past, present and future.

All this theoretical stuff is offset by some nicely unfussy performances. Adams communicates Banks's sense of loss as well as her questing spirit, while Jeremy Renner makes a laid-back foil as physicist Ian Donnelly (Adams and Renner pictured above). Whitaker's Colonel Webber is the embodiment of military literal-mindedness, where orders are orders and hare-brained excursions by mad scientists are strictly verboten. Still, the flick could use a little less conversation and a little more action.

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• Snowden theatrical release reviewed on theartsdesk

@SweetingAdam