IT'S WORLD WAR II and Eugene Morris Jerome, a Jewish kid from Brooklyn on his way to boot camp, has only three objectives before being shipped off to who knows where -- "to become a writer, not get killed and lose my virginity."

Army-bound Eugene is playwright Neil Simon's alter ego in "Biloxi Blues," the second chapter in the autobiographical trilogy which began with "Brighton Beach Memoirs." The four-star production encamped at the National Theater for the summer certainly earns its stripes, with a cast as uniformly fine as the original Broadway company.

Eugene accomplishes two of his goals but finds that becoming a writer is a bit more difficult. Eugene's engaging trek toward adulthood in the Army makes for Simon's most mature work to date -- the playwright still gets his extraordinary quota of laughs per minute, but he integrates them naturally into more serious dramatic situations.

Populated with the usual tossed salad of fellows, the boot camp barracks at Biloxi, Mississippi provide rich material for Eugene's faithfully kept "Secret and Private Memoirs."

We meet the bully, of course, the loudmouth and the dreamer, and the complex Arnold Epstein, "the worst soldier in WWII," a cerebral guy who makes things tough for everyone by rejecting Army logic and clinging to his own dignity. There's also a seemingly sadistic platoon sergeant who divides his charges to conquer them. Later, Eugene has a riotously edgy encounter with a hooker and meets his first sweetheart at a USO dance.

At face value, these are all stock situations from every old Army movie, but Simon draws them vividly and shades the play with some darker, more difficult themes, as Eugene and the others are confronted with anti-Semitism, homosexuality and other intimate aspects of close-quarters Army life. Eugene, who often confides in the audience, expresses doubts about himself as well, afraid that he is becoming a neutral observer instead of a full participant in life.

William Ragsdale makes the role of Eugene fully his own, in a charming performance marked by alertness, comic vulnerability and a flavorful Brighton Beach accent. As Arnold, Andrew Polk impresses with quiet dignity and intensity. John Finn is an entirely believable Toomey, never making the sergeant into a cartoon bad guy. Kathy Danzer is delightful as the genial hooker Rowena; Marita Geraghty is everyone's first love as Daisy Hannigan, Eugene's "perfect girl"; and the other sad sacks in Eugene's barracks are perfectly cast as well.

BILOXI BLUES -- At the National Theater through August 3.