The Last King of Scotland casts Forest Whitaker as Amin, and this is one of those times where the right actor is given the right role. The main character, though, is Nicholas Garrigan (Narnia’s James McAvoy), a Scottish doctor who heads to Uganda to escape a less-than-nurturing home life. There he meets and is attracted to a married doctor named Sarah Merrit (Gillian Anderson), who shares his idealism for medicine but not his fascination with the country’s new leader. Together they work at a small clinic, providing much-needed treatment for the poor.

When Amin suffers a minor injury in a car accident, Garrigan is brought in to treat him. During the process, the president is impressed with the doctor’s no-nonsense approach. He offers Garrigan a position as his personal physician. The doctor declines, but is eventually seduced by Amin’s charm and promises of improved medical care for Uganda’s people. Before long, Garrigan is much more than a doctor; he becomes one of Amin’s most trusted allies, consulting on things that go beyond medicine. He gets off on the fact that this powerful – and often gregarious – leader has brought him into the inner circle.

That starts to change once Amin shows his true colors. When he’s not being charming, he is paranoid, hateful, and vindictive. Innocent people are killed under his orders. All Asian people are ordered to leave Uganda. His enemies are brutally murdered. Garrigan wants to leave the country, but Amin won’t let him. He also tries to hide the fact that he’s had an affair with one of the president’s wives, Kay (Kerry Washington). The situation grows more complex as Amin learns to turn on his charm for the media, in an attempt to distract the world from what he’s really doing. Garrigan tries to find a way to escape and, if possible, tell the truth about the Ugandan leader.

Rather than taking a straightforward biopic approach, The Last King of Scotland tells Idi Amin’s story by telling that of Nicholas Garrigan. (Garrigan is a fictional character created for the Giles Foden novel on which this movie is based). We see the film through the doctor’s eyes as he is seduced, then ultimately repulsed, by the charismatic president. This is an interesting angle to take. We know from news footage that Amin could turn on the charm when he wanted to. We also know that numerous atrocities were committed under his regime. By making Garrigan the central character, the film can show both sides of Amin’s personality while still maintaining a moral position. Additionally, the movie says something about the seductive power of evil. Many of history’s great villains were also quite charismatic; it’s how they got people to go along with, or at least silently accept, their actions. Last King powerfully explores this duality between congeniality and brutality.

Director Kevin McDonald comes from the documentary world, having also made Touching the Void and One Day in September. He effectively brings a documentary-like approach to the filming of this story. There are moments where you feel like you’re eavesdropping on a real moment rather than watching a reenactment. This goes a long way toward giving the film a pulse. The last 40 minutes in particular are intense, as the screws tighten exponentially for both Amin and Garrigan.

Forest Whitaker has been a solid actor for years, but this is his moment to shine. Finally given an honest-to-goodness standout role, he is nothing short of extraordinary. Whitaker perfectly conveys both sides of Amin’s personality. You understand why people would be drawn to him, and also how scary he could be. While Whitaker is enjoying the bulk of critical acclaim for having the showier part, James McAvoy is no less effective. I like the subtlety he brings to Garrigan. You can feel the moral quandary the character experiences as he tries to reconcile the friendly, trusting man with whom he has associated himself with the reprehensible actions that man commits.

I think The Last King of Scotland could have given even more of an impression of the horrific things that Amin did and how his people suffered. Also the relationship between Garrigan and Merrit doesn’t really lead anywhere. (The subplot with Kay Amin is much more effective.) Despite those minor flaws, this remains a gripping and resonant story. Even today, the world has larger-than-life leaders who are responsible for things like genocide and terrorism. We don’t always understand who they are as people or how they do such awful things. This movie puts us right next to one such person, showing us in frightening detail how it happens.

( 1/2 out of four)

The Last King of Scotland is rated R for some strong violence and gruesome images, sexual content and language. The running time is 2 hours and 1 minute.