Intelligently detailed, impressively mounted, absorbingly told and undeniably gripping, Sydney Pollack’s The Interpreter is a very satisfying movie—unless you’re seeking something more than a thriller that only superficially engages its political subject. It’s both a compliment to and a criticism of Pollack and the screenwriters (Charles Randolph, Scott Frank and Steve Zaillian of Schindler’s List) that the movie primes you for more than it delivers.

Nicole Kidman plays Silvia Broome, an émigré from an African nation, Matobo, who works as an interpreter at the United Nations. Returning to her booth to fetch her things after a standard alert has closed down the General Assembly, she overhears two men whispering in the dialect of her country. She realizes that they’re planning to assassinate Matobo’s leader, Zuwanie (Earl Cameron), when he comes to New York.

What makes the premise more interesting—and the movie potentially far more complex than most political-intrigue melodramas—is that Zuwanie, originally a revolutionary hero who rescued Matobo from a tyrant, has become as vicious as his predecessor. Tobin Keller (Sean Penn), the Secret Service agent assigned to investigate Silvia’s report, learns that members of her family were killed by one of Zuwanie’s landmines and that her brother is still at home, working underground with the forces that want to depose the ruler.

The film has some extraordinary sequences, including the opening, set in Matobo: Two men whose identities we learn only later arrive for an arranged meeting at a soccer stadium, where barely adolescent boys show them a stash of Zuwanie’s victims entombed inside the building. The meeting turns out to be a trap: the men are gunned down while their cohort, a photographer ordered to wait in the car (played by the talented French actor-director Yvan Attal), snaps clandestine photos of their murder.

Later Pollack shoots a terrifying scene in which Silvia winds up on a Brooklyn bus with an exiled government minister she suspects may have had her brother killed, two of Tobin’s men and one of the assassins she overheard, who is carrying a bomb. This episode is clearly meant to evoke a celebrated scene in Hitchcock’s 1936 Sabotage (an adaptation of one of the great political novels, Joseph Conrad’s The Secret Agent) in which a boy is sent, unknowing, to deliver a bomb on a delayed bus.

Hitchcock used to say that he lost his audience’s sympathies when he exploded the bomb and killed the innocent lad; three-quarters of a century and much bitter history later, the audience fully expects that if a character enters a public place with a bomb, the worst is bound to occur.

In fact, The Interpreter evokes several of Hitchcock’s thrillers. But despite its apparent seriousness of purpose and some thoughtful dialogue between Silvia and Tobin, it doesn’t add up to much. The tension between her stated idealism (which, she protests when he uncovers her past, has led her away from Matobo and to a job at the UN) and her revulsion at Zuwanie’s regime calls for a more profound exploration. So does the fact that the movie has us rooting for Tobin and his crew to derail the murder of a loathsome politician. In the final act, Pollack and the writers dismantle that irony.

What we’re left with is a great deal of excitement and a performance from Penn that, after his overwrought, overlauded work in Mystic River, is the real thing. As an intuitive man who is still shaken by the untimely loss of his wife, Penn suggests the bone-deep ache of grief in unexpectedly tender ways. The idea is that Tobin’s and Silvia’s losses enable them not only to understand each other but to counsel each other. It might work if a more interesting actress than Kidman were involved. She is skillful at conveying a certain kind of neurosis, but as a woman struggling to bury old political fervors she isn’t even in the ballpark. If she were on Penn’s level or anywhere near it, The Interpreter might get close to the kind of depth it flirts with.