Dressed in a gray suit with an American flag pin in his lapel, then-Commerce Secretary Carlos Gutierrez said the modest two-lane span that U.S. taxpayers paid for would be "a critical transit route for trade and commerce" between Afghanistan and Tajikistan.

Today, the bridge across the muddy waters of the Panj River is carrying much more than vegetables and timber: It's paved the way for drug traffickers to transport larger loads of Afghan heroin and opium to Central Asia and beyond to Russia and Western Europe.

Standing near his truck in a dusty patch on the Afghan side of the river, Yar Mohammed said it was easy to drive drugs past the Afghan and Tajik border guards.

"It's an issue of money," Mohammed said, to the nods and grins of the small group of truckers gathered around him near the bridge at Nizhny Panj. "If you give them money, you can do whatever you want."

The roots of the global drug trade are often a murky tangle of poverty, addiction, violence and corruption. However, it's clear why the dirt-poor former Soviet Central Asian republic of Tajikistan is on the verge of becoming a narco-state.

After the U.S.-led invasion of Afghanistan in 2001, the United States and other Western powers looked the other way as opium and heroin production surged to record levels, making Afghanistan by far the world's biggest producer.

Much of the ballooning supply of drugs shipped across Afghanistan's northern border, up to one-fifth of the country's output, has traveled to and through Tajikistan. The opium and heroin funded rampant corruption in Tajikistan and turned the country, still hobbled by five years of civil war in the 1990s, into what at times seems like one big drug-trafficking organization.

Every day last year — extrapolating from United Nations estimates — an average of more than 4 metric tons of opium, which can be made into some 1,320 pounds of heroin, moved on the northern route. Put another way, the equivalent of nearly 6 million doses of pure heroin — at 100 milligrams each — is carried across the northern Afghan border each day.

After it's cut with other substances and sold on the street corners and in the apartment stairwells of Russia and Western Europe, the main retail markets for Central Asian heroin, that could produce at least 12 million doses.

Nevertheless, it's clear even to a casual visitor at the bridge that neither the Afghan or the Tajik border guards have much interest in curbing, or even inspecting, the exports that pass in front of them.

In fact, as the Afghan drug supply has grown, Tajik seizures have fallen. In 2004, Afghanistan produced 4,200 metric tons of opium, and some 5 metric tons of heroin or its equivalent in opium were seized in Tajikistan, according to U.N. figures. Last year, with Afghan cultivation rising to 7,700 metric tons of opium, Tajik authorities seized less than 2 metric tons of heroin.

Although the United States wields enormous influence in both countries, their drug problems have taken a back seat to the war against the Taliban. Until the past year, Afghanistan's growing drug production was at best a midlevel priority for Washington, and the U.S. hasn't pressed Tajik President Emomali Rahmon to rein in his country's drug trafficking, Western officials said. Nor, they said, has any other Western government with troops in Afghanistan.

All along the Afghan-Tajik border, smugglers for years have thrown sacks of heroin over the Panj River, waded across when the water is low, set up flotillas of car tires and used small ferries or footbridges.

The U.S.-financed bridge has made drug trafficking even easier, truck driver Mohammed said with a toothy smile: "You load the truck with drugs."

The ferry that used to operate at Nizhny Panj carried about 40 trucks a day. The bridge can carry 1,000 vehicles daily.

Organized crime groups now are focusing on using official checkpoints to move their drugs, a senior official at the Tajik State Committee for National Security said, speaking to a recent meeting of Central Asian counter-narcotics officers.

"Especially through the Tajik-Afghan bridge on the Panj River," Davlat Zarifov said.

Zarifov apparently didn't know that a reporter was present, and he declined further comment and quickly walked away.

To try to get the Tajik government's side of the story, a McClatchy reporter approached Sherali Mirzo, the official in charge of the country's border guards, a man with a full mustache and medals across his uniformed chest. Mirzo said he didn't talk to the media.

Rustam Nazarov, the director of the country's drug control agency, said in a brief interview that the declining heroin and opium seizures suggested that there was less trafficking of those drugs through Tajikistan, an analysis that the facts on the ground would seem to contradict.

Nazarov, however, did allow that, "There is corruption in Tajikistan; no one denies that. Unfortunately, we have some civil servants who are corrupt."

A few days later at the Afghan-Tajik border, as the sun began to dip below a horizon framed by jagged mountains, Mohammed Zahir, an Afghan truck driver, gave a simple explanation for how drugs get across the bridge.

"People involved with the drug business know the guards," Zahir said. "Before sending their drugs across, they pay them money."

A second driver, Qand Agha, chimed in: "If high officials on the border weren't involved, then people like me couldn't take drugs into their country."

Down the road, a line of trucks was crossing the bridge.

'DENGI, DENGI'

Sitting in a $40,000 SUV with soft leather seats and a dark orange paint job, a man named Negmatullo hitched up his shirtsleeve to show the sore on his arm from the heroin he'd been shooting up. He fiddled with his designer sunglasses, absentmindedly brushed his hair and said in a junkie's mumble that, "If you pay someone at the border, you can bring drugs up."

Negmatullo, a thin man with dirty blond hair, had just come out of a drug treatment clinic in the town of Kurgan-Tyube, a halfway point between the border and the Tajik capital of Dushanbe. He asked that his last name not be used for his own security.

When Negmatullo was asked why guards and other Tajik law-enforcement officials would be susceptible to corruption, he rubbed his fingers together and muttered "dengi, dengi," Russian for "money, money."

The car's license plate flashed by as Negmatullo pulled away; it was number 7777, a calling card of those connected to the president's inner circle.

The spoils of the drug trade are as obvious as the shiny new BMWs speeding down the dusty roads that cut from south to north across the steppes of Tajikistan, passing hunched old men who tend the cotton fields with hoes. It's an ancient setting: Alexander the Great and his men conquered parts of the territory in the fourth century B.C, and they're said to have crossed the Panj River by floating on leather hides.

These days, in a nation where some 50 percent of the population makes less than $41 a month, there's a steady stream of new Mercedes and Lexus sedans, not only in Dushanbe, but also in the hamlets that dot the way to the Afghan border.

Locals say the cars often are given in trade for loads of heroin shipped north to the Russian border. The stuff is easy to get.

"You can just take two bags over your back, walk across the Panj and bring them back filled with heroin. It's no problem," said Vazir, a Tajik who was released from a Russian prison last February after he was caught trying to take 600 grams of heroin through a Moscow airport. During an interview in Dushanbe, he asked that his last name not be used because he feared retribution.

Vazir continued: "You can give your bag of heroin to one of the guards, and he will carry it across for you."

'A CULTURE OF IMPUNITY'

The supply chain appears to reach far beyond hustlers such as Vazir. Many Western officials and Tajik observers suspect that the Rahmon government controls the drug trade.

"I don't know if the president is involved personally, but he gives the percentages to different groups for what they can do," said one Western diplomat in Dushanbe, who like others spoke only on the condition of anonymity because of the sensitivity of criticizing the regime. "Just go to the airport. There are bags of heroin going through unchecked. . . . People are pretty open about it. There's more and more a culture of impunity."

After the Soviet Union fell in 1991, Russian troops continued to patrol the Tajik border. They withdrew from the area in 2005 after the Tajik government demanded that they leave — though it allowed them to stay in other parts of the country — asserting that as a sovereign nation Tajikistan was capable of securing its own frontiers.

An assortment of local conscripts replaced the relatively professional Russian contingent, which trained and financed the Tajik officer corps.

"You have conscripts earning maybe $3 a month stretched out over 1,344 kilometers of border" — 835 miles — said another Western diplomat in Dushanbe, discussing the problem of drug dealers paying border guards to look the other way. "It's obvious that if you need to eat, corruption is an option."

Some Russian and Western officials said privately that the Tajik government wanted the Russians out of the way to ensure a larger supply of opium and heroin.

It was a move designed to gain "hold of a bigger part of the drug trade," one Western diplomat in Dushanbe said.

"Frankly speaking, there were forces in the government of Tajikistan who wanted to replace the Russian troops with Tajik troops to allow more holes in the border," said a Russian official in Moscow who travels regularly to Tajikistan and has high-level contact with the Tajik government. "It was to make the penetration of drugs easier."

The State Committee for National Security, Tajikistan's version of the KGB, took control of border enforcement in 2007 and almost immediately barred the country's Interior Ministry and drug control agency from access to the border region.

'THERE IS ALWAYS GOING TO BE A TRADEOFF'

When a McClatchy reporter drove to the border at Nizhny Panj to do interviews, troops turned him back because he didn't have official permission. A border guard supervisor in plainclothes pulled the reporter's driver aside and suggested in a menacing tone that the driver was a spy. The Tajik government later denied McClatchy permission to visit the southern border.

The reporter resorted to crossing the bridge into Afghanistan with a routine visa, and he saw no evidence that Afghan or Tajik officials were inspecting trucks for contraband.

Despite the public nature of the drug trade and related corruption in Tajikistan, however, the West has done relatively little to pressure President Rahmon.

Some Western officials acknowledge that it's the result of a political tradeoff: No one wants to risk alienating Rahmon on the issue of drug corruption because his authoritarian regime's cooperation is important for preventing Islamic militants from using the Tajik-Afghan border as a sanctuary.

"The Americans want to have a logistics base here, so do you think they're going to pressure the government about corruption?" said William Lawrence, a chief adviser for a U.N. Afghan border-management program based in Dushanbe. "The answer is no."

The U.S. Embassy in Dushanbe declined to comment, but a State Department official said that such balancing acts were common.

"There is always going to be a tradeoff based on different foreign-policy objectives, different security objectives, the tolerance for different types of corruption, different levels of corruption," said the official, who spoke on the condition of anonymity because of diplomatic protocol. "I don't think the situation in Tajikistan, frankly, is that much different than the rest of Central Asia in terms of these types of tradeoffs."

A second Western diplomat in Dushanbe was more blunt about Western governments ignoring reports on Tajikistan's official complicity in drug corruption.

"We send reports every month to our capitals, very negative, but they don't (care)," said the diplomat, whose country has troops in Afghanistan. "Because it's a so-called stable country leading to Afghanistan, we accept it."

The diplomat said that his country had funded projects to help train and equip the Tajiks to deal with the drug problem. The United States and other Western nations have done the same.

This month, for example, the U.S. ambassador to Tajikistan broke ground on a $2.5 million project to overhaul the border guard training academy in Dushanbe. The American Embassy said in a recent news release that it had implemented more than $37.5 million of initiatives to help Tajik law enforcement since 1992.

However, the second Western diplomat said, there isn't much arm-twisting to make sure the Tajik government cracks down.

"We don't dare to say to the president, 'We give you money for anti-corruption but the first thing you see on the streets is these police taking bribes,' " the diplomat said. "Nobody says, 'We'll give you money for border security, but in three years we want to see a reduction in drugs.' "