Somebody could write a fabulous play about Benedict Arnold. James A. Culpepper hasn't. Treason at West Point never gets beyond exposition and tactics. The characters rarely come alive; some of them never even come into focus. The cast does a fine job with what they have, but the show's a bore.

The trick in writing a chronicle play is to use the historical events to show off the characters of the leading figures. But Culpepper never even deliniates his protagonist. We learn in the first scene that Arnold is suspicious and quick tempered, but also a valiant general. Later on we learn he has a tendency to live beyond his means. But we never see how or why his meaner characteristics overcome his nobler ones.

Idle in Philadelphia, while less capable generals are being given commands--and losing them--Arnold is persuaded by his wife that Washington thinks him a "crippled fool." She suggests he go over to the British. Ten thousand pounds are offered. He accepts. But we never see whether it's avarice or anger that provokes his treason. And, even more inexcusable, Culpepper does nothing whatsoever with the scene in which Arnold decides.

The playwright draws "the incomparable Peggy Shippen," Arnold's wife, with equal fuzziness. She tells us herself she is audacious; she appears to be rather stupid. Her relations with her husband are left vague. Just how much does she influence him? Does he suspect her former liaison with Major Andre, the British intelligence officer? Does he mind?

The same lack of depth mars all the American generals. Washington curses but he never struggles. One expects more eloquent agony than the sputters with which he responds to each defeat.

Only with the British does Culpepper give his cast definite characters to portray. But I wonder just what purpose the farcial staff conference serves. It is the only enjoyable scene, but how it relates to the rest of the play isn't clear.

Novelists can tickle their readers with ambiguities, but a dramatists should at least indicate to his players how to behave. Director Robert Chapman and the Treason company have had to decide for themselves.

Robert Ginn has the hardest job, and he almost succeeds. His Arnold is consistent, believably cantankerous, but rather flat. He doesn't pick a particular interpretation to project.

Francine Stone, as Peggy, does a creditable job, but she doesn't make more of her character than Culpepper has.

The only really satisfying performances were turned in by John Ross as Clinton, and Richard Backus as Andre. Each adopts a manner and sticks to it. By the end of the play, I actually got to like Clinton.

John Toye (Arbuthnot), and John McDonnell (Cornwallis) were the only others who managed to create characters; the common soldiers played their scenes with extraordinary aplomb. George Hamlin tried hard to make something of Washington, but with the lines he had it was hopeless.

Donald Soule's ultra sparse set--a rock and a couple of flags--must rank as a triumph for the reigning make-the-Loeb-look-big-and-empty school of designing. I hope it marks a turning point.