Over a village in southern Afghanistan, an American helicopter circles and lands. Armed men jump out and huddle near a compound wall. A translator speaking through a megaphone announces a police action and says the men are coming in.
It's one of the most politically unstable corners of the world, but the men aren't on a typical mission for troops in Afghanistan. In fact, they aren't even soldiers, and, despite what it looks like, this is not a U.S. military operation. This is the American Drug Enforcement Administration.
"It's never just about seizing and destroying the drugs," team leader Frank Tarentino told "Nightline." "It's really more about the taking down, dismantling, the disruption of organizations. ... This operation will start to generate intelligence and information that will assist for following operations."
For nine years the DEA has quietly toiled away in Afghanistan to stop drug traffickers. But now the agency is at the center of the Obama administration's strategy in Afghanistan.
This elite group of DEA Foreign-deployed Advisory and Support Team members -- nicknamed the FAST Team -- has taken its drug-fighting expertise to Afghanistan because the country is the source of an estimated 90 percent of the world's heroin.
Money from that drug trade is believed to generate $125 million a year and fund the Taliban and the growing insurgencies in Afghanistan and Pakistan, as well as possibly al Qaeda.
Tarentino leads his men on four-month deployments in Afghanistan. Their mission is to collect evidence and build legal cases against drug dealers. Often, they target smaller dealers to build larger cases.
In compounds raided by the agents with "Nightline" cameras rolling, the FAST team seized opium, heroin, hash, weapons and evidence, and arrested several suspects.
In one case, suspects fled, leaving weeping women and children behind, and the tea they were drinking still warm.
In another case, agents arrested a man for possession of hash.
"I need for you to talk to the women, that they are placing the husband under arrest for illegal possession of narcotics," Tarentino told his translator as a suspect was handcuffed and a nearby woman and baby cried.
The arrested man spoke to his family in Pashto.
The interpreter explained that he told his distraught wife that he was only being taken away for questioning -- but Afghan drug laws are strict, and he was likely going to jail for 15 years. The suspect was blindfolded and put in a helicopter.
"We have successfully removed many Afghans, roughly eight, to the U.S. for prosecution," said Tarentino. "Most notably, the largest trafficker in all of Afghanistan is sitting in a U.S. prison right now."
DEA agents must pass a grueling multi-week tryout to make the team. While in-country, they train like soldiers, with target practice and other drills.
Tarentino is a former Army captain. He is currently on his sixth deployment in Afghanistan and has deployed on other assignments around the globe. After retiring from the military, Tarentino joined the DEA and was working for the agency in New York on 9/11.
"Like the rest of the country, we all felt the need to get involved and this was the best way for me to do it," he said.
More than half of the FAST team has military backgrounds. Part of their job is to train a special Afghan police force tasked with drug interdiction.