To the chagrin and anger of Turkish officials, a new scourge of illegal narcotics is once more sweeping out of Turkey to nurture the habit of addicts in the United States and Western Europe.

Unlike the past, when Turkey's own opium fields were to blame for much of the heroin reaching the West, the narcotics this time are not home-grown.

Instead, Turkey is acting as a transit point for an unprecedented amount of traffic from the east. It flows across the hard-to-patrol Turkish mountains from a region narcotics agents have dubbed "the golden crescent," an arc of loosely governed land that stretches from Iran, through Afghanistan to western Pakistan.

What has alarmed international narcotics agents is that the production -- and assumed traffic -- out of the "crescent" is of a magnitude never before encountered.

The drug production makes the past renowned crops from the "golden triangle" on the border of Burma, Thailand and China seem like a backyard victory garden by comparison. It dwarfs the "French connection" of 10 years ago, which was fed by Turkish poppies until the Ankara government, stung by international opinion and diplomatic arm-twisting, agreed to a program of opium control that has guaranteed that their own production would serve only the legal pharmaceutical trade.

Western narcotics experts estimate that because of the general lack of authority in the traditional growing areas of the "crescent" countries, production has gone wild. They estimate that for the past several years the three nations have been producing more than 3.3 million pounds a year of opium gum, the brown narcotic-laden sap bled from the opium poppy bulbs.

Since it takes more than 11 pounds of gum to manufacture about one pound of morphine base or, later, heroin, that means that the "golden crescent" is capable of dumping up more than 300,000 pounds of heroin a year on world markets.

To understand the magnitude of that figure, experts point out that the estimated annual heroin consumption of the 400,000 addicts in the United States is just under 9,000 pounds a year.

"We have never been faced with a situation like this before, "said one Western official. "We have never had to contend with such a large uncontrolled production in any one area in the past."

The experts say that once the raw opium is harvested it is transported by backpack, mule, horse or four-wheel drive vehicles to the Turkish border with Iran.It is then smuggled through the mountains to buyers in eastern Turkey, many of whom run their own primitive labs to break down the gum into more easily transportable morphine base or heroin.

The drug buyers are free enterprise amateurs or professionals working for organized crime groups abroad.The drugs are then shipped through Ankara and Istanbul by all available means: international trains and truck trailers through the Balkans; freighters to the Italian or French coasts, or by paid carriers, among the more than 1 million Turkish workers living in Western Europe.

Narcotics officials so far have managed only to make a dent in the trade. Turkey's own understaffed drug police have intercepted about 220 pounds of heroin since the beginning of the year and have uncovered dozens of transformation labs in the eastern provinces. Four months ago about 170 pounds were intercepted hidden in plastic bags in the bowels of a trailer truck in Yugoslavia on its way from Istanbul to Frankfurt, West Germany. Another 83 pounds was found on a ship docking at Trieste. And Western European narcotics agents have recently managed to close down five sophisticated labs in Italy that were using morphine base brought in from Turkey to make heroin for shipment to the United States.

Narcotics experts fear, however, that this is just the tip of the iceberg and that the dismantled "French connection" has been reconstituted into a much larger and more complex operation.

Scattered evidence supports this theory. Chemical tests have indicated that in many U.S. cities up to 50 percent of the heroin intercepted is traceable to the "crescent."

Turkish officials are extremely sensitive to publicity about the problem. They had hoped to escape their reputation as the world's narcotics connection when they suspended opium growing in 1972. Although it was resumed two years later, the government placed all crops under rigid licensing and enforcement controls.

But the new drug flows across Turkey has revived the government's sensitivities.

Western officials are full of praise for the efforts of the Turkish government and its narcotics police in fighting the heroin trade. But they admit that given the nation's economic crisis and its more pressing need to fight terrorism, the government's means are limited even if its will is not.

The problem clearly goes beyond Turkey's borders and responsibilities. And Western officials are pessimistic about being able to do much.

"You cannot fight narcotics successfully without a concerted program of international cooperation, both to curb production and to enforce (punishment of) violations," said one Western diplomat. "With the political instability reigning the way it does to the east of here, it is difficult to be very hopeful."