Sergei Kaledin's 1988 Russian novella "Construction Battalion" had the rare privilege of being the only work banned by Gorbachev. And watching Gaudeamus, a loose adaptation of it by Saint Petersburg-based director Lev Dodin, it's not hard to see why. Strongly informed by the antiauthoritarian backlash that followed the Soviet debacle in Afghanistan, it portrays the Red Army as a silly, corrupt, pointless institution led by fools and martinets and populated mostly by confused, frightened, undisciplined boys whose only break from their monotonous and overregimented life is a steady diet of vodka, sex, singing, and more vodka. Gaudeamus starts out with lots of sweet and whimsically physical comedy; in a moment of exquisite Python-esque madness, the company commander, loath to look his men in the eye, delivers an impassioned speech to a line of boots. But what I relish most about the play is the way the humor darkens and then turns savage as we seen the men slowly become unhinged. Some indulge in sweet, impossible fantasies--one boy dreams of dancing a pas de deux with a local girl on a grand piano--while others turn to more nasty and brutish entertainments, as when a night of drinking ends (it is strongly hinted) with a gang rape. Gaudeamus, with its frank portrayal of aggressive social chaos and loveless sexuality, is reminiscent of the angry, honest movies, plays, and novels--Catch-22, M*A*S*H, Bringing It Back Home--that appeared in this country just before and during our own military misadventures in Vietnam. Hardly the sort of fare, I am sure, Gorbachev and his cronies wanted circulating during what turned out to be the dying days of the Soviet Union. Athenaeum Theatre, 2936 N. Southport, 722-5463. Opens Wednesday, October 19, 7:30 PM. Through October 22: Thursday, 7:30 PM; Friday-Saturday, 8 PM. $24-$32.