At the center of The Lives of Others is Gerd Wiesler (Ulrich Mühe), a quietly proud Stasi officer who has spent his life and career in unquestioning service of the East German government. His service is not blind: Wiesler is a man who serves with full knowledge of what his State does to its enemies -- indeed, he teaches interrogation at the Stasi University, and is applauded by students for his ability to break suspects. He's not a mindless functionary but an intelligent man who sincerely feels socialism is the best path for his country, and that the Stasi provides a crucial service. Not a proponent of belligerent proselytizing, Wiesler simply observes the world around him, judging with his sad eyes when he sees others whose commitment to the State stems from self-interest rather than true devotion to its principles. When his superior and old friend Anton Grubitz (Ulrich Tukur) becomes increasingly focused on his own advancement within the Stasi hierarchy, Wiesler offers the dour disapproval of a parent, quietly asking the other to remember why they first joined the Party.

Dragged by Grubitz to the theater one night on yet another of his friend's steps towards self-advancement, Wiesler sees a play by Georg Dreyman (Sebastian Koch in a charming, low-key performance), one of the few high-profile, truly talented playwrights in the country fully committed to the Socialist cause. After spending most of of the show watching Dreyman, Wiesler becomes vaguely suspicious of the man's true feelings and, through a series of accidental circumstances, finds himself charged with setting up and directing surveillance on Dreyman's apartment.

Sitting in a dark warehouse surrounded by listening equipment and flickering closed circuit monitors, Wiesler is drawn into Dreyman's world, focusing on the writer and his actress girlfriend (Christa-Maria Sieland, played by Martina Gedeck) with a childlike intensity. Not only is he being forced to see one of his subjects as a whole human being for the first time, but he's also encountered a suspect to whom he doesn't immediately feel superior. Wiesler is fascinated by his subject: A passionate, intelligent artist who seems, at least at first, to genuinely support the government. Despite being blissfully unaware of the surveillance, Dreyman repeatedly misses even the most private opportunities to criticize the government in East Berlin. Though he rarely tries to persuade others to abandon their rebellious views, he nevertheless preaches caution and control, clearly believing, if not in the State, at least in reality: Were he to oppose the government, he would lose his comfortable existence, and would never work again. Given the choice between rebellion and acceptance, Dreyman sees no choice at all; he's as apolitical as possible, making few compromises, violating no rules, and working in peace.

All of that changes, however, with the suicide of Albert Jerska (Volkmar Kleinert), a director friend who had been blacklisted years earlier for endorsing an unspecified anti-government document. When Jerska dies, Dreyman realizes that he needs to take action, and his true feelings come rushing to the surface. Listening in horror as the man he has come to admire says words that should at the very least earn him interrogation (at worst, he could be made to disappear), Wiesler is suddenly out of his depth. No longer the distant watcher, he begins pulling the strings of Dreyman's life, secretly controlling and directing events to protect him; in the process, he betrays his own government, and turns his back on decades of committed service. To the immense credit of first-time writer-director Florian Henckel von Donnersmarck, Wiesler has no Eureka! moment. Instead, he's just a man reacting with his gut; for the first time in years, Wiesler acts without first running his life through his internal State filter.

What's most impressive about The Lives of Others is how smoothly it blends politics with both the traditional elements of thrillers and unabashed sentimentality. Von Donnersmarck's film powerfully condemns the Stasi -- often with cutting, sudden humor -- while also shamelessly tugging our heartstrings with its story of one man risking everything for another. In addition, the movie contains strong elements of 1970s conspiracy thrillers (particularly The Conversation) with its central theme of surveillance, and unrelenting air of doom. The proof that the combination is successful can be seen in the film's massive success at this year's German Film Awards, the German equivalent of the Oscars: If a movie centered around a sympathetic Stasi officer can be critically and publicly acclaimed in a country still alive with memories of the horrors wrought by that institution, it must be a very good film indeed.

Crucially, sympathy for Wiesler is created without ever compromising the movie's condemnation of the Stasi, or soft-peddling Wiesler's past actions. While Von Donnersmarck's writing is part of that subtlety, most of the credit must go to Ulrich Mühe, whose performance in the role is as nuanced as it is powerful. A slight, compact man, Mühe's Wiesler is physically very orderly: He keeps his jacket zipped up under his chin and carries himself ramrod straight, his large, expressive eyes made cold by years of practice. Everything in his life runs according to routine, from his travel to and from his bland, anonymous apartment to his nightly rituals of dinner alone and visits from the occasional brusque prostitute. When his life begins to meld with Dreyman's, though, Wiesler undergoes small physical changes, from the softening of his eyes to slight losses of control over his body. What once was a well-oiled Stasi machine is suddenly subject to uncontrollable burst of emotion, and Mühe makes every tiny moment count, breaking our hearts with a simple twitch of his arm. The fact that Mühe himself spent his pre-unification adulthood being watched by the Stasi only renders his work that much more impressive. The performance stands out in a well-crafted film full of solid acting; both Mühe and The Lives of Others are unforgettable.