Cambodia's singleminded effort to seal itself off from the world and make itself totally independent is unlike any other political experiment in the 20th century.

"If you look at our country through the mirror of your own, you will not understand us," Deputy Pime Minister Ieng Sary told me during my recent twoweek visit. "Out country is poor, very poor, and our people are still poor."

But a lot of countries are poor. And what makes all that has taken place in Cambodia particularly difficult to understand is that no one seems able to offer a coherent philosophical basis for the extreme upheaval that has taken place.

The goal, leaders explain repeatedly, is to make Cambodia within 20 years a self-sufficient agricultural nation that relies on no other country, and that can ensure all of its people a comfortable if not a lavish existence.

But the price -- the human and cultural cost -- has been tremendous.

No one seemed able to explain satisfactorily why if was necessary to empty Cambodia's cities following the Communist victory in 1975, and send shopkeepers, scholars, engineers and housewives off to agricultural cooperatives to become laborers in the fields.

Nor could I find any explanation of why it was necessary for thousands of Cambodians to die from disease, malnutrition and summary execution in the course of fashioning this new Cambodian society.

Most of the evidence of attesting to the horrors that have taken place in Cambodia has been furnished by the thousands of refugees who have fled the country, and I saw little indication of these problems during a very strictly supervised government tour.

But I lived in Cambodia for two years, and perhaps the most telling indication of what has taken place here is that I saw not one familiar face during my two-week stay.

I also found that the Buddhist culture, which was the foundation of Cambodia for centuries, has been totally done away with, and this left me with the sense that I was in a country which had lost what I once considered its soul.

Before 1975, the wat or pagoda was the center of life in Cambodia. Children were educated and orphans were raised there, and the saffron-robed monks were looked to for the ministration of troubles.

Today, the pagodas I saw were being used as granaries. The monks, I was told, have been sent out to work like other Cambodians in the fields. One unique feature of the new Cambodia is that money has been withdrawn from general circulation. Instead, goods are exchanged through a sophisticated barter system.

I got an explanation of how this works at the Meas cooperative near Kompong Cham, one of the few we were allowed to visit. The 300 residents of this cooperative grow rice in nearby fields and weave cloth for brightly colored checked scarves and sarongs.

Since this cooperative produces more rice than its residents can eat, the rice is "sold" to the central government in Phnom Penh. The cooperative recevies a credit for the rice -- 4 riel per ton -- and uses those credits to purchase things it cannot produce such as gasoline for its tractors.

The accounts of each cooperative are kept on a national registry in Phnom Penh, an official told us.

"That is not so unusual," he said. "In your country you don't use money often. You use credit cards and checks."

Cooperatives like Preah Meas are administered by committees. These generally have three members with one person acting as a president.

At Le Bo cooperative in Takeo, we were shown what officials hope will become the norm for Cambodia in the future.

In seemed to be almost entirely selfsustaining. Besides its clean huts, the cooperative had a large bamboo chicken coop, neat vegetable plots around the homes and, we were told, a pigpen farther out in the fields.

Near the communal dining hall and patio was a foundry where agricultural implements were produced. Inventiveness was in evidence everywhere. One man was peddling a bicycle bellows while another melted down brass from spent American ammunition casings.

Just that morning, the entire cooperative had held a political education meeting.

"We passed several resolutions," the cooperative president said. He told me the cooperative members had agreed to complete the harvest by the first week in January, and had discussed how best to divide up the tasks and meet the deadline.

Production and work quotas seemed to be discussed more often at these political education meetings than Communist philosophy. At times, in fact, production seemed to be almost a national obsession.

As we drove down Route 4, the road leading to the seaport of Kompong Som, I noticed that one lane had been blocked off. A work brigade was using the cement for winnowing and sorting the rice from the chaff after harvest.

Besides agricultural cooperatives, Cambodia has set up cooperatives to manage plantations and factories. I asked repeatedly why the leaders inaugurated such a radical cange in the country immediately after the war. In the West, experts believe that the early economic writings of Khieu Samphan, the current Presidium president, were the inspiration.

I was told that was not correct.

"During the war," one official said, "we had to put our people into cooperatives to ensure that we had enough food for them and our army. The American bombing was severe and the Vietcong was trying to buy the rice as well. That is also why we did away with money."

One of the places I particularly wanted to visit was a collective rubber plantation.

Cambodia has always been rich in rubber and gemstones, and one of the questions I wanted to ask was why the new government was not taking advantage of these natural resources.

On a visit to the Cham Can Do rubber plantation cooperative in Kampong Cham province, I discovered that rubber was under full production and is now being exported. Sapphires, however, are not being mined, I was told, because it would require too much manpower.

At Cham Can Do, we were first escorted through a former French-run rubber factory which was operating smoothly and efficiently the day of our tour. Discarded machinery from around the country had been put to use there.

From previous reporting I had done on rubber manufacturing in Cambodia, this operation looked to me to be both efficient and producing highquality rubber.

Officials later told us that Cambodia was exporting 35,000 tons of rubber to Singapore, China and North Korea. They said Cambodia was also exporting kapok to Japan, and rice to Madagascar and other African nations.

The lasting impression I came away with of rural life in Cambodia was a tableau of scores of peasants, clad in black, tending abundant rice fields. Their leaders constantly told us that the people had become masters of their own lives by becoming "masters of the water."

"If you control water, you do not suffer drought in the dry season or floods in the rainy season," one official said. "You control disease because the water runs quickly and smoothly. You allow fish to be abundant. The whole atmosphere is fresh."

The government magazine, "Democratic Kampuchea," and official films are replete with photographs of the man-made dams and irrigation canal systems that have been built around the country by work brigades since 1975.

Without this irrigation system, the officials said, there would have been no possibility of becoming self-sufficient in food so quickly.

"We could not wait to send our engineers to higher schools, that would have taken years," an official explained at one of the three dam sites we visited. "We had to learn through experience and these are crude but they suit our purposes."

At a dam site I visited in Battambang province, the gate had failed to control the water during torrential rains, and the reservoir's water had spilled over the dam and caused considerable damage.

"We were lucky the dam survived," one local leader said.

But for the most part, the dams seem to work. This year, Cambodia suffered its worst droughts in 70 years, losing 10 per cent of its crops, officials told us. But I could see as we toured the countryside that replanting had already begun, and the government said it still plans to export rice.

"Unlike Vietnam," one official said, "we will never have to beg for aid."

From all I had heard before my trip about how poorly the new system in Cambodia was working, I was a bit surprised by the general level of production throughout the country.

I have no way to be sure, of course, that all the figures given me were accurate. But the evidence I saw suggested that the figures could not be too misleading.

The methods that the new rulers of Cambodia have used to get their system working are an entirely separate matter that will continue to be discussed -- and condemned -- by much of the world for years to come.

But the economic system, I am forced to condlude, seems to be working.