There should have been a question mark in the title of the CBS News documentary, "What's Happened to Cambodia," to be seen at 8 tonight on Channel 9. The program asks more than it answers about the fate of a nation that seems to have disinherited itself from its own past and where atrocities are allegedly being committed in the name and guise of revolution.

A key problem with the report is that it's like a profile for which the subject refused to be interviewed; CBS News was not allowed inside Cambodia, now called Democratic Kampuchea, with cameras or reporters, and so we see correspondent Ed Bradly standing outside a barbed-wire border and speculating on what is happening on the other side.

In addition, a number of experts, of varying credibilities, were interviewed by Bradley and Peter Collins about the conditions in Cambodia under its new rulers, and CBS News purchased about 45 minutes worth of film - not all of it included in this report - shot in Cambodia by a team from Belgrade TV that was allowed to take a "guided tour" earlier this year.

Bradley introduces this footage by pointing out that the Cambodians had only permitted these "fellow communists" from Yugoslavia limited and supervised access to the country. Yet even this managed look at the Cambodian nation provides a stark and striking contrast to the views of the capital, Phnom Penh, as it was before the Vietnam War.

Today, Bradley says, the city is "a ghost town, depopulated by design as part of a total revolution." There are no stores, theaters or television; all the people have been put to work on buildings, dams and irrigation and are fed a steady diet of state propaganda over government-controlled radio.

Refugees who escaped from their country describe brutalities committed against those accused of making "mistakes" under the new order. One, a 16-year-old boy, details with an eerie lack of outward emotion the way his parents were beaten to death in front of him and he himself left for dead.

Still, the report stops short of stating as fact that there are the kind of "massacres" now going on in Cambodia that led columnist Jack Anderson to propose recently that the perpetrators be "hauled before the bar of world opinion" and "named to the Hall of Infamy alongside Adolph Hitler and Joseph Stalin."

Obviously, CBS News was thwarted in attempts to deploy all the resources of broadcast journalism on this report. Nevertheless, and annoyingly, Bradley tries to come up with one of those equivocating closing summations that says absolutely nothing but gives the impression that something has been said.

"Is it genocide?" he asks. "We'll let you pass that judgment. And where will it lead? Even the leaders can't say." One doesn't expect a State Department briefing on this topic, but certainly a more thoughtful analysis on the basis of available evidence was possible.

Finally Bradley closes on what he calls "a personal note" that is about as personal as stainless steel. He spent two years in Southeast Asia, much of it in Cambodia, he says, and when he watched the Yugoslavian footage "I kept trying to see if I could find any faces I remembered. I couldn't. He might as well have said "Something has happened, but we don't know what it is."