In addition to being a fine director, Ron Howard is a good sport. Between adaptations of Dan Brown bestsellers The Da Vinci Code (2006) and Angels & Demons (slated for May 2009), the filmmaker has been thoughtful enough to grace us with something infinitely riskier and, for the audience at any rate, far more rewarding. Frost/Nixon may just be the past year’s most entertaining piece of mainstream cinema.

Based on Peter (The Queen) Morgan’s acclaimed London and Broadway play, the movie recounts (and occasionally augments) events surrounding David Frost’s 1977 series of interviews with Richard Nixon, the first he’d given since resigning from office nearly three years earlier. Michael Sheen and Frank Langella reprise their stage roles, and the work both actors do is award worthy.

Howard, of course, has a knack for real-life dramas. Apollo 13 and A Beautiful Mind are among his best, but Cinderella Man may be closest in spirit to his latest, given its gladiatorial subtext. As the film gets underway, we are given to understand that popular English television host Frost has fallen on hardish times. His syndicated American talk show has been canceled, and the program he’s doing in Australia is on its way to meeting the same fate.

That’s when the real Frost came up with the plan that would put him back on top. Members of the press establishment scoffed at the notion of this jet-setting playboy sitting across from the controversial former president, and the networks balked, but Frost wouldn’t take no for an answer. He paid Nixon $600,000 — largely out of his own pocket — hustled the commercial time himself, rounded up a producer and team of researchers, and then assembled his own syndication deal. Nothing like it had ever been done in the history of broadcasting.

Howard and Morgan permit themselves a modicum of poetic license in places. The chronology of the four interviews, for example, has been tweaked to lend them a suspense-building sports-match tension, and the effect is mesmerizing. A few scenes (such as one featuring a rambling late-night phone call to Frost from an intoxicated, self-pitying Nixon) are total inventions, but they feel as psychologically and emotionally accurate as anything recorded on tape between the two men. You needn’t know a thing about American history to find the movie fascinating.

That’s because Sheen and Langella convey everything you need to know about these unlikely sparring partners through their brilliantly crafted performances. Langella channels his paranoid, lonely, megalomaniac character, never for an instant merely imitating him. As was the case in 2007’s Starting Out in the Evening, the actor is at the absolute top of his game.

Sheen’s performance is equally inspired. Anyone who remembers watching Frost on TV is likely to find the man behind the scenes a far more nuanced figure than his on-screen persona suggested. He loves beautiful women, is almost as fond of his fashionable wardrobe, and parties like he’s paid to — but also works tirelessly and is a quick study. The Frost we meet here isn’t a gotcha showboat. Sheen convinces the viewer he wants to maneuver Nixon into an apology to the American people in large part because he comes to care about the man and believes sincerely that “unless you say it, you’re going to be haunted for the rest of your life.”

The dynamic between the two as the cameras roll is spellbinding, their exchanges as white-knuckling as any of the confrontations in the ring Howard choreographed for Cinderella Man. A first-rate cast of secondary players only adds to the depth and richness of the drama. Kevin Bacon is superb as the ex-president’s righthand man, former Marine Jack Brennan; and so are Toby Jones in the role of his agent, Swifty Lazar, and Kate Jennings Grant as stalwart Nixon press assistant Diane Sawyer. Given Sawyer’s place in TV journalism today, it’s intriguing to watch her send death rays in Frost’s direction.

On the other side, the always watchable Oliver Platt and Sam Rockwell play Bob Zelnick and James Reston, journalists who teamed up with Frost to unearth Watergate dirt that would catch their interview subject off guard and, in Reston’s words, “give Richard Nixon the trial he never had.” They’re like a latter-day Woodward and Bernstein.

He’s never mentioned by name, naturally, but the specter of another disgraced commander in chief makes a cameo appearance. Howard reminds us of history’s tendency to repeat itself (if we let it) when he plays footage of civilian casualties inflicted during the invasion of Cambodia. Frost reminds Nixon that “one of the principal justifications you gave for the incursion was the supposed existence of the headquarters of the entire communist military operation — which proved not to exist at all.” Sound familiar?

David Frost is still active. How cool would it be to see him sit across from Dubya one of these days and give him the trial he never had? That’s one sequel I’d give anything to see.