Both countries have isolated agricultural populations vulnerable to coercion by insurgents financed by narcotics trafficking. In Colombia, the world's largest producer of cocaine, the FARC turned to drug funding when support from fellow communists dried up with the collapse of the Soviet empire. Here in Afghanistan, the global leader in opium production, the radical-Islamist Taliban became drug-dependant after being driven from power in 2001 during the opening days of Operation Enduring Freedom.

Despite international efforts to cut foreign financial support for the Taliban and a crackdown on the movement's activities in Pakistan, the Taliban have derived newfound wealth from the heroin trade. A new U.N. report estimates that the Taliban reap as much as $70 million a year from the sale of precursor chemicals, taxes levied on opium farmers, "protection fees" for heroin processing laboratories and "product deliveries." Some U.S. Drug Enforcement Administration officials here believe Taliban drug revenues are more than twice that amount. They point out that the lucrative drug trade also has resulted in corruption on a massive scale within Afghanistan's national and provincial governments. This nexus of narcotics, crime and terror has prompted a dramatic change in allied strategy that provides new opportunities for success in Afghanistan.

Coalition commanders, cognizant of growing public discontent about the course of the war, are focusing on how opium is funding the Taliban and adversely affecting prospects for a successful counterinsurgency campaign. Gen. Stanley McChrystal has all but abandoned efforts to eradicate opium poppy cultivation because it was raising resentment against his troops and the Afghan government. Now coalition efforts have shifted to targeting drug kingpins -- and their connections to the Taliban.

In the year since we were last here, the U.S. Drug Enforcement Administration has more than quadrupled its presence in Afghanistan. Nearly 100 DEA special agents, intelligence specialists and trainers are deployed, not only in Kabul but also throughout the country. Small, well-armed and highly mobile DEA foreign-deployed advisory and support teams, or FAST, are working closely with U.S. and NATO special operations units, Afghan commandos and specially trained counter-narcotics police.

DEA intelligence experts and a growing network of informants -- something other U.S. agencies have been unable to duplicate -- are providing detailed "actionable" information -- "target sets" -- that can be exploited rapidly in "capture-kill" missions. Precisely targeted raids by highly trained specialists are creating havoc within the hierarchy of the opium-trafficking networks that help to fund the Taliban. As one FAST member put it to me shortly after a night operation that took down a heroin-hashish "bazaar" and bagged more than a dozen narco-terrorists, "We're already hurting them, and we're just getting started."

Because these operations are quick, low-profile and self-contained, they serve as a "force multiplier" for Gen. McChrystal's conventional forces. Perhaps equally important, nearly every mission undertaken by these units results not only in drug seizures but also in captured weapons, recovered IEDs and new intelligence about Taliban activities.

Interdiction operations such as these are not being conducted in a U.S.-NATO vacuum. U.S. trainers are deployed to train, mentor and advise Afghanistan's fledgling counter-narcotics police. The Afghan Sensitive Investigation Unit and National Interdiction Unit now number more than 275 law officers -- many of whom accompany DEA agents and special operations forces on raids.

Gen. McChrystal's assessment of the situation in Afghanistan -- presented this week to the White House -- acknowledges how difficult the campaign here has become as U.S., allied and Afghan casualties mount. There are calls from the left and the right -- just as there were in 2006 during dark days in Iraq -- to throw in the towel, to "get out and get out now." That's not what we're seeing and hearing from the soldiers, sailors, airmen, guardsmen and Marines we have encountered here. And that's not what we're told by the DEA and special operations personnel with whom we are embedded.

Cutting the flow of narco-funding for this insurgency won't, in and of itself, win the war in Afghanistan. The country still has only one paved highway, and the near total collapse of basic infrastructure is indicative of how badly the U.N. and the "international donor community" have squandered billions here. But if we are to see the "light at the end of the tunnel" in Afghanistan, bankrupting the Taliban is a good place to start.