No doubt the United Nations complex in New York is a serious place. Even detractors would concede the diplomacy conducted there and under U.N. auspices around the world is weighty, if often ineffectual, stuff. 

Judging by The Interpreter, a stolidly competent thriller starring Nicole Kidman as a translator in the U.N.'s employ, that sense of gravity is contagious. What fails to register clearly, thanks to an obfuscating script, is exactly why her character, Silvia Broome, cares so much. The smart but vague screenplay is a generic manifesto for the U.N.'s mission of using talk instead of violence to resolve problems facing the international community. 

At times, viewers may be reminded of two exceptional films, All the President's Men and The Fugitive, or a Hitchcock movie. That promise isn't realized in the end because director Sydney Pollack is more proficient at generating suspense than following through on it. The tension he builds is window dressing for an abstract story. You might say the plot is mealy-mouthed -- or perhaps overly diplomatic. 

The two leads have the weight of the world on their shoulders. Retrieving her belongings in the sound booth of the General Assembly one night, Silvia overhears whispers of a plot to assassinate the leader of the (fictional) African nation of Matombo, who is to deliver a speech there soon. Sean Penn plays the Secret Service agent -- back on the job two weeks after his semi-estranged wife dies in a car accident -- assigned to investigate the threat.

Turns out cagey Silvia is quite familiar with the strife-ridden country. Not only does she speak the language, having been born there, she has some murky connection to the political players. Two rebel factions are suspected in the murder plot and Silvia's convenient involvement naturally troubles Penn's investigator.

While red herrings are dangled, the countdown begins to the climactic speech. Pollack takes full advantage of his unprecedented access to the General Assembly, staging showy set pieces involving security operations in and around the building. There are overhead shots of Manhattan streets and motorcades, and security details open limousine doors in synchronization.

The movie's highlight is a long scene involving a city bus containing Silvia, an exiled Matomban, and Federal agents. Pollack can take pride in that sequence, although his decision to cast himself as a Secret Service official was ill advised. (The Screen Actor’s Guild should pass a disapproving resolution.)

The only character that isn't circumspect and who displays a sense of humor is the wisecracking agent played by Catherine Keener, in a departure from her usual roles. Needless to say, Kidman looks great with or without headphones on, and she lives in a lovely Greenwich Village apartment. Her accent is spot-on and she's believable toddling about Manhattan astride a mustard yellow Vespa.

Penn's theatrical gravitas is appropriate; but the character's personal tragedy seems random. There's no opportunity for the audience to invest in his relationship with his dead wife. He and Sylvia bond over having lost people close to them -- a pretty common common denominator. Their private relationships and feelings are thrust onto the world stage without sufficient detail. The Interpreter holds your attention yet doesn't penetrate beneath the first layer of anything or anyone. 

Silvia's belief in her work at the U.N. is noble yet she remains too mysterious to be admired. Once again, Hollywood goes to great lengths to tell us what we already know: Dialogue is preferable to war; violence is bad and leaders let us down by resorting to it. That's the source of Silvia’s disillusionment. It's not enough for an incisive political thriller.

(Released by Universal and rated "PG-13" for violence, some sexual content and brief strong language.)