Something deeper than race, and more disturbing, lies at the heart of this chilling film. Masculinity, machismo, male dominance was the raw uncivilised force that drove the history and fuels this fictionalised account of Idi Amin’s Uganda.

Deeper because ethnicity and colour divides human beings into a multiplicity of groups: gender divides us definitively into two. And as a man there is nothing more disturbing or indisputable than the fact that the instinct for violence, brutality and love of physical power resides almost exclusively in men. Modern history has no female tyrant to match Amin, Hussein, Pol Pot, Hitler, Stalin et al. And it is worth noting that this male dominance drives almost every major religion; from tea-and-cakes Anglicanism to the misogynistic excesses of the Talleban.

TLKOS is only the most recent major film where the most horrific images are of death and mutilation inflicted by men on women. And however true to the cultural context, women in this movie are no more than possessions or playthings to be used, abused then thrown away. And as ever in these contexts in movies, there is a thread of sexual imagery woven into the fabric of the film. This is not to doubt the intention or integrity of the film, but simply to remark upon facts of its representation.

Restless, newly-qualified Scottish doctor Nicholas Garrigan escapes the airless future of partnering his Calvanist, joyless father in the family General Practice. A random finger on a globe lands him in Uganda working in a volunteer hospital in the 1970’s just as the charismatic, larger-than-life Idi Amin overthrew Milton Obote’s corrupt regime.

Having treated Amin for a minor injury Garrigan finds himself ‘adopted’ and drawn into the tangled paranoia of Amin’s fledgling dictatorship. Hopelessly naïve about the escalating brutal reality around him, Garrigan believes Amin values his straight-talking honesty. An illusion soon destroyed by Amin’s gathering paranoia. Elevated from personal physician to political adviser, it never dawns on Garrigan that Amin not only relishes the fact and the image of a subservient white man to use and dominate, but also fully appreciates the irony.

A mixture of disillusionment and alcohol leads to the madness of an affair with Amin’s youngest of three wives. Her resulting pregnancy adds both to the urgency of Garrigan’s desperate efforts to escape Amin’s clutches and dramatic tension to the film. A once supportive British Foreign Office seeks to solicit Garrigan to assassinate their one-time protégé now that they can no longer control him. A horrific tragedy overcomes Garrigan’s resistance and he gives Amin lethal tablets to take.

Amin takes Garrigan with him to Entebbe airport where Palestinian hi-jackers are holding a planeload of hostages. Here he reveals to Garrigan that he knows of the Scotsman’s disloyalty domestic and political and exacts vengeance on him in typically brutal fashion. Helped by a Ugandan doctor friend Garrigan miraculously escapes with the non-Jewish hostages for whom Amin has called up a plane. Historically but not within the film, two days later Israeli commando’s daringly rescued the remaining Jewish hostages from a distinctly uncertain fate at Amin’s hands.

Macdonald handles this ‘inspired by true events’ narrative very well. Cinematographer Anthony Dod Mantle captures the reds and ochres of the African lansdscape to create a cauldron-like, oppressive visual tone. And editor Justine Wright’s editing has both pace and rhythm.

What makes this film extraordinary of course is the riveting performance of Forest Whitaker as Amin. His overwhelming physical and psychological presence commands the screen. In sheer size and features he is a ringer for Amin anyway. But this fine actor, with an in-built air of danger and menace, brings the lethal volatility and unpredictability of an unstable megalomaniac, chillingly to life on screen. Indeed if Whitaker moves away from the real Amin in any way it is perhaps that the real man often looked like a buffoon and vaguely ridiculous. Whitaker’s Amin never looks either, however absurd the situation or his behaviour. His own amblyopia (lazy eye) adds a constant, unsettling sense of ambiguity to every expression and glance. Certainly Whitaker’s Amin has a fascinating, charismatic charm not obvious from actual film footage of the man. He replaces the real Amin’s apparent instinctive cunning with a much more menacing and terrifying sense of deeply disturbed intelligence. There is an interesting example of this: when an already beaten-up Garrigan is about to be strung up by butcher’s hooks though his chest he says to Amin “you’re just a child, that’s why you are so fucking scary.” Now this remark sounds absolutely right about the real Amin but not of Whitaker’s. There is a deeper, more deliberative, psychotic intelligence at work in Whitaker’s portrayal that makes his Amin so chillingly terrifying.

For me, James McAvoy’s Garrigan is too callow making his stronger characteristics at times unconvincing. But to be fair, anyone would be overshadowed by Whitaker’s commanding presence and mesmeric performance. Considering the brutal reality of Amin’s regime, Macdonald is not gratuitous in his horrific imagery. But again it is an image of a mutilated woman, Kay, that lingers troublingly in the mind after leaving the cinema.

Amin’s treatment of the Ugandan Asians demonstrated his own instinctive racism. And though not emphasised in this film, tribal favouritism also informed his choice of targets for his brutality. Just as it was to do so appallingly 30 years later in Rwanda. But though not the subject of the film, almost unremarked in fact, I return to the premise from which I started. Male dominated tribes, religions, governments and armies, whatever may divide them, are united in one hateful perception – that women are dispensable and disposable to the point of a degenerate indifference by men to the suffering of those who gave them life.