Still under the domination of the Soviet Union in matters of foreign policy, Bulgaria is changing in every other way. Its agricultural system is decentralizing in the direction of the Hungarian model. Its economy is becoming more consumer-oriented.
In recent years Western culture has invaded the capital. And although state pronouncements are stridently anti-American, Bulgarian officials advise visitors to see the ever-increasing trade with the West as ''a material expression of our foreign policy.''
Now celebrating its 13th centennial of nationhood, this Balkan country of 9 million has -- since World War II -- doubled and tripled production of every basic commodity. At the same time, it has reduced its agricultural work force from 88 percent of the population to a modest 22 percent.
While Poles have long had to wait in line outside near-empty food stores and while rationing has been instituted in neighboring Romania, grocery stores in Bulgaria are full. And the countryside here appears far less poverty-stricken than in Romania, southern Yugoslavia, or parts of Greece.
''Our agriculture works from bottom to top: The collectives decide on their own structure of production; the state gives them limited guidelines only; and we hope that our obligatory tasks will even lessen further,'' says Nickolai Nickolov, department head for management improvement in the National Agrarian Union.
A Western banker with wide experience in the Balkans comments that ''Bulgarian agriculture officials have a better idea of what's going on in the field than their colleagues in other countries. They have a sound pricing system, the free market mechanism is allowed to work somewhat. You even get the feeling that these guys in Sofia might actually have worked on a farm at one time in their lives.''
Bulgaria exports large amounts of produce to the Soviet Union. But since 1979 it has tripled its purchases of agricultural goods from the United States. In large part, this has been due to bad weather conditions, which caused shortfalls in corn and wheat.
''We imported because we didn't want our consumers to suffer,'' an official said.
In the view of foreign observers here, the most impressive thing about the Bulgarian economic system is the amount of self-criticism that is permitted in official newspapers.
''When it comes to the execution of domestic policy, the Bulgarians are openly hard on themselves,'' one embassy staffer observes.
In the realm of culture, Western films, fashions, and hair styles have become common features in Sofia. This is a marked change from eight years ago, when this reporter was here last.
English is fast becoming the most popular foreign language, although Russian is still mandatory. And while the Soviet Embassy is situated in a suburb, a crowd of Bulgarians constantly hovers over the display windows of the American Embassy in downtown Sofia.
Concerning foreign policy, a Western political attache remarks that the Bulgarians ''have an ambivalent attitude toward the United States and the West. Privately, relations are very good but, publicly, relations have deteriorated since the Soviet invasion of Afghanistan.''
Bulgarian officials intimate that their trade policy is under fewer restraints than their diplomatic policy, and thus is a truer reflection of their intentions.
''Trade is one way in which a small country like Bulgaria can help improve the political climate between bigger countries like the United States and the Soviet Union,'' said Nicolae Stefanov, an official at the Foreign Trade Ministry.
Trade with the West is always increasing, albeit modestly. Bulgarians complain that American and Canadian quota systems hamper more dramatic developments in this sphere. They are disappointed that North American firms haven't come forward to establish joint ventures with Bulgaria. But Western officials here note that the ''vague wording'' of the Bulgarian statute is not sufficient to satisfy Western businessmen.
Often scorned in the West as the Soviet Union's most subservient satellite, Bulgarians counter by citing the economic benefits of total reliance on the Soviets. They have been able to obtain crude oil and nuclear technology through barter trade with the USSR.
The word ''freedom'' has only an economic connotation here. One Foreign Ministry official with the rank of ambassador says freedom only has meaning in terms of ''a rising living standard for Bulgarians.''
As one resident American here puts it, ''If you use their system of values, there isn't much to complain about here.''