Afghanistan and its neighbors - Pakistan, Iran, Turkmenistan, Tajikistan and Uzbekistan - and other states in Central Asia and the Persian Gulf are believed to consume about half of all drugs produced in Afghanistan. At least 5 percent - about 1 metric ton - of heroin imported into the United States yearly originates in Afghanistan, according to U.S. seizure data.
In Pakistan, the promise of drug riches draws people of all walks of life. Among those on trial on drug trafficking charges are a former member of Pakistan's National Assembly, the owner of an English language daily and an influential politician.
Here in Quetta, about 85 miles from the Afghan border, the drug trade has a daily impact on residents' lives. Addicts are said to number in the thousands, and their need to buy heroin and other drugs has increased thefts and killings, authorities say.
Tons of heroin and other drugs enter Pakistan in the remote desert and mountains outside Quetta, where anti-narcotics forces and drug smugglers play violent games of cat and mouse. Smugglers cross the mountains into Pakistan by night, moving swiftly in three- or four-car convoys armed with automatic weapons, surface-to-air missiles and rocket launchers.
"They never give up without a fight," said Lt. Col. Abdur Rashid Khan, director general of the Baluchistan Anti-Narcotics Force. "They go all out to escape the ambush. But most of the time we are successful."
Khan clicked through his unit's successes: In 1999, his men captured 23 metric tons of drugs. Last year, they intercepted 27 metric tons. This year, they have captured 13 metric tons. And in the past three years, the courts have prosecuted 158 drug cases, 55 percent of them resulting in life sentences.
Khan estimated that Pakistan's anti-narcotics forces capture about half of the drugs smuggled across Afghanistan's border.
Some of the heroin, no doubt, will find its way beneath Jinna Road Bridge in Quetta, where there are plenty of loyal customers.
"Sure, I want to leave this habit. It is very bad. I would love to leave it. But I can't do it now," said Kamal Mustafa, 45, who begged a visitor for rupees.
"If you don't smoke it, it is like taking a fish out of water," Shah said. "And if a fish is out of water, it cannot live."