“So the U.S. military was in the business of enriching warlords at the expense of others and always at the expense of poor farmers,” said Blank.

Until 2009, Washington favored a more aggressive eradication approach that frequently had the exact opposite effect as intended, fuelling corruption at the local level. Since Afghanistan's central government is so weak, eradication programs were typically enforced or administered by the country’s powerful warlords, with the tiny fraction of crops that were eradicated usually belonging to their political enemies.

“All efforts at counter-narcotics in Afghanistan have failed,” said Jonah Blank, an Afghanistan expert at the RAND Corporation in Washington, D.C. “You can’t wage a counterinsurgency and conduct serious opium eradication at the same time. What you’re doing is impoverishing farmers, you’re saying, ‘Trust us, and by the way we’re going to destroy your crops and leave you with nothing.’”

The record-setting year was hardly surprising. Since the U.S. forced the Taliban out of power in 2001, opium cultivation in Afghanistan has generally been on the upswing.

“In past years, surges in opium poppy cultivation have been met by a coordinated response from the U.S. government and coalition partners, which has led to a temporary decline in levels of opium production,” Special Inspector General John Sopko said in the letter sent to Secretary of State John Kerry and other Obama administration officials.

Afghan farmers grew a record 209,000 hectares of opium poppy in 2013, up from the prior record in 2007 of 193,000 hectares, according to the latest statistics from the United Nations Office on Drugs and Crime. The country’s opium poppy cultivation was valued at $3 billion in 2013 – a 50 percent increase from the previous year – as Afghanistan continues to produce nearly 90 percent of the world’s supply.

Opium poppy cultivation in Afghanistan has hit a record-high, the U.S. Special Inspector General for Afghanistan Reconstruction (SIGAR) wrote in a letter on Tuesday, calling into question the efficacy of the $7.6 billion U.S. counter-narcotics effort aimed at curbing the illicit trade – an important source of funding for the Taliban insurgency, and a major contributor to the country’s rampant corruption.

The Afghan government, which has minimal reach and legitimacy in much of rural Afghanistan, is hardly in a position to directly crack down on opium cultivation – even if the trade exacerbates Afghanistan’s deeply-embedded corruption (Transparency International has rated it the most corrupt nation in the world) and bankrolls Taliban violence.

In 2009, U.S. policy shifted away from efforts to wipe out opium crops altogether in favor of middle-ground tactics thought to be more in sync with the "winning hearts and minds" premise of U.S. counterinsurgency strategy. Crop substitution programs, for example, are meant to help opium farmers transition to legal crops without breeding resentment among those who have grown increasingly dependent on the drug trade to survive.

These softer tactics are more palatable to Kabul, but the latest data suggest they have proven ineffective. With opium prices and addiction rates high in Afghanistan and neighboring countries, growing opium poppy continues to be more profitable for farmers in the desperately poor hinterlands of Afghanistan.

"The strategy failed on both fronts, because the Afghan government didn't have the needed political will to go after prominent drug lords, and farmers did not receive the right incentives to abandon opium cultivation in the most unstable provinces," said Haroun Mir, the founder of Afghanistan's Center for Research and Policy Studies, in an op-ed for Al Jazeera on Tuesday.

The SIGAR letter noted that U.S.-funded agricultural development, which has helped to expand Afghanistan's arable land, may actually be bolstering the opium trade. Analysts suspect that the deep wells and irrigation pumps that the U.S. has provided for Afghan farmers often end up for sale on the black market. According to Blank, “You can give farmers other things to grow, but they’ll need roads and irrigation, and there’s no way of enforcing that this stuff only be used for legitimate agriculture.”

The last time opium trafficking and production was markedly reduced in Afghanistan was in 2000 – the last year the Taliban was in power. The movement's success in cracking down on opium indicates that a stronger authority in Kabul could be more effective.

Many hope Afghanistan’s new president, Ashraf Ghani, will at the very least be more committed than his predecessor, Ahmed Karzai, who was seen as a volatile and unreliable partner for any and all U.S. efforts in the country.

But there are signs that even Washington has lost some of its resolve after more than a decade of counterproductive efforts. In a speech at Georgetown University last month, Sipko suggested that the counternarcotics effort had simply fallen off the radar for both the U.S. and its Afghan partners, citing recent U.S. military roadmaps for Afghanistan that scarcely address the burgeoning opium trade.

“By every conceivable metric, we’ve failed," he said. “Given the importance of this problem, I was astonished to find that the counternarcotics effort isn’t a top priority during this critical transition period and beyond."

Michael Kugelman, a South Asia expert with the Wilson Center in Washington, D.C., said that might not be so surprising: “Afghanistan has got security challenges, the Taliban insurgency, and major economic challenges. Certainly narcotics pays a role, but in and of itself, it just doesn’t constitute a front-burner policy issue.”