If ever a drama depended on its last 15 minutes, this one does. Peter Morgan's "Frost/Nixon" leads up to the final 1977 television interview in which the former president apologizes to the American people for his role in the Watergate political scandal. If that final scene doesn't work, all that comes before is wasted.

The script plays a relatively compact 90 minutes and is shot through with humor but is all prologue to the final confrontation. In those final moments Nixon — like the bull in the arena — loses his will to live, and Frost — the lightweight talk-show host — demonstrates that show business and politics are separated by only a thin line.

That moment of high drama works in the current Manoa Valley Theatre production directed by Bree Bumatai. It also gives Bill Ogilvie as Richard Nixon and Ned Van Zandt as David Frost some excellent material on which to test their acting mettle. But much of the prologue — at least a good hour of it — is less engaging.

Early dialogue makes a connection to ancient Greek drama, where the principal character is often brought down by exaggerated pride and self-confidence. But the preliminary action mostly gives the two leads an opportunity to develop their characters.

Van Zandt's chore is less demanding, mainly requiring him to conquer a boxy, double-breasted suit and an abundance of hair and manage a British accent. Ogilvie must create the essence of an historical figure remembered by many without creating a comic caricature.

The results are sufficient to create consistent opposing personalities, although they fall short of being rounded living portraits. Frost is played as an entertainer who is far out of his league and risking career failure in mismanaging the interviews. Nixon emerges as a wily and crafty former power, given to drink as he festers over his fall from prominence. The first interviews are a failure, with Nixon lapsing into 20-minute monologues that stray far from the original questions.

A late-night phone call from Nixon to Frost triggers the final confrontation. Deep into alcohol, a gruff and boozy Nixon tells Frost they both have spent a lifetime hoping for approval from snobs and challenges his interviewer to a showdown from which only one of them can walk away.

It promises to be a verbal gunfight. Last-minute research into overlooked transcripts provides the ammunition.

That surprise information causes Nixon to lower his guard and gives Frost the opportunity to coax him toward his final admission: "I let down the American people and I will have to carry that burden for the rest of my life. My political life is over."

Russell Motter connects the scenes with narration and Allen Cole strikes some sparks as Nixon handler Jack Brennan.

As a slice of dramatized history, "Frost/Nixon" draws extra wattage from the recent Presidential campaign, but not enough to elevate the only American president ever to resign from office to the level of a truly tragic figure.

Joseph T. Rozmiarek has been reviewing theater since 1973.