WHAT WOULD Christmas be without the Russians? "Spies Like Us," the Dan Aykroyd-Chevy Chase espionage spoof, becomes the third film to feature our favorite foes in the last 10 days. It's beginning to look like Rudolph's nose is red for a reason.

Aykroyd and Chase play a pair of fledgling operatives who take on the Soviet highway patrol in what begins as a romp of a road show -- the Road to Duchambay -- but suddenly turns into a semi-comic plea for mutual understanding, like a lame "Dr. Strangelove."

But Aykroyd and Chase, teamed on the big screen for the first time, are funny even when tripped up by the clumsy shift in emphasis. The two flunkies are recruited by a secret service when they're caught cheating on their civil service exams. They think it's a promotion.

The two parachute into spy boot camp where they learn to stay afloat at high speeds. Their drill instructor teaches them how to survive radical-vertical impact simulation; they are dropped off a building -- much as David Letterman dumps watermelons off the mystery tower -- until they get it right.

Aykroyd's wife Donna Dixon is the love interest, the brunt of tacky burlesque humor when Chase mauls the raving beauty in a tent in Pakistan where the spies tackle their first assignment. After debasing Dixon, the comics, masquerading as doctors, perform an appendectomy on a chieftain's brother. From a how- to book under the operating table, Aykroyd reads, "The first step is to shave the patient." So he lathers up the guy's beard.

The costars operate in the best of comic traditions, borrowing from Bing and Bob (with Hope making one of his surprise guest shots), but they can't counter the political potholes with pratfalls.